In this episode, toxic gases from harmful bacteria in the colon allow Cancer Cell to grow stronger. However, as the Lactic Acid Bacteria arrive in the colon to eliminate the harmful bacteria, the toxic gases disappear, causing Cancer Cell to become weaker. At the same time, Memory T Cell performs his ultimate technique, T Cell Perforin Cannon Punch, to fire a beam that damages Cancer Cell. The beam also wipes away the label on Cancer Cell’s shirt, prompting Regulatory T Cell to recognise him as an enemy and turn against him. Without the protection of Regulatory T Cell, Neutrophil, who breaks out of his pod, easily kills Cancer Cell, ending the threat.

To learn more about Memory T Cell’s ultimate technique, see this blog post from season 1 of the anime where I explain what cancer is and how T and NK cells can kill cancer cells. I also explained in the last blog post how the immune system can be suppressed to promote the growth and metastasis of cancer. In this blog post, I will talk about colorectal cancer which is where the last two episodes of season 2 takes place. I will explain how common colorectal cancer is, how it develops and how it is treated. I will then talk about the role of the gut microbiota and the various metabolites in increasing or decreasing the risk of colorectal cancer.

In this episode, Neutrophil, NK Cell and Memory T Cell get trapped by Cancer Cell who takes them to his lair in the colon. They try to fight against Cancer Cell and his paper puppets, but Cancer Cell sends in Regulatory T Cell to defend him. Regulatory T Cell successfully fends off attacks from NK Cell and Memory T Cell, defeating them in the process. Meanwhile, Cancer Cell traps Neutrophil in a pod to question him about his existence. Following this, Cancer Cell evolves to become more dangerous, planning to kill the body to take the other cells with him.

This anime episode is a continuation to the Cancer Cell episode from season 1 which I covered in a previous blog post. In that blog post, I explained what cancer is and the features that cancer cells possess to endlessly proliferate and metastasise. In this blog post, I will talk about two more features that can further promote cancer growth and spread: the tumour microenvironment and immune escape. I will then talk about the role of regulatory T cells in promoting cancer growth and discuss how cancer treatments can enhance immune responses against cancer. 

In this episode, Neutrophil, Normal Cell and NK Cell visit the large intestine. They notice that the large intestine smells bad due to toxic gases being released by harmful bacteria. Normal Cell leaves Neutrophil and NK Cell to seek the place where the last Lactic Acid Bacterium lives. Normal Cell visits the gut epithelium, where Intestinal Epithelial Cell and Goblet Cell work desperately to keep the gut epithelium strong despite persistent attacks by harmful bacteria. Despite their efforts; though, the gut epithelium breaks, forcing the cells to run away as harmful bacteria enter through the broken epithelium.

As discussed in my introductory blog post on the gut microbiota, the gut microbiota serves a variety of functions that are essential to optimal human health. One of the main functions of the gut microbiota is to maintain the integrity of the gut epithelium. In this blog post, I will talk about how the gut epithelium serves as an important physical barrier to prevent gut contents and bacteria from entering the human body before explaining how its integrity is maintained. I will then explain how the breakdown of the gut epithelium can lead to inflammatory bowel disease (IBD).

In this episode, Lactic Acid Bacterium, washed away from Normal Cell in the last episode, is picked up and tended by Dendritic Cell. Meanwhile, Normal Cell, Neutrophil and NK Cell move to the small intestine, where they encounter Influenza Virus that mutates and becomes resistant to the immune cells’ attacks. Just as the immune cells fall into despair, the dressed-up NK Cell suddenly appears with Lactic Acid Bacterium. By consuming the biscuits produced by Lactic Acid Bacterium, Dendritic Cell is motivated to spread embarrassing photos of immune cells’ past lives, motivating the immune cells to eliminate Influenza Virus.

Influenza is an infection that I covered in a previous blog post as part of an episode in the last season of Cells at Work!. In that blog post, I talked about what the influenza virus is and how T cells are activated by dendritic cells to eliminate influenza-infected cells. This blog post builds on the previous blog post, where I first provide more information about the influenza virus itself. This will lead to the big mistake the anime makes in regards to the different ways influenza viruses can evolve. Following this, I will then explain what cytokines are and how they assist in immune responses against pathogens.