Despite crankily brushing off AA2153 on his first day, Chief Gastric Cell eventually starts addressing him by name in recognition of all the effort he's put into his work.
When U1196 tells J1178 that she and the other imported White Blood Cells are fighting to leave the body to the native White Blood Cells, implying that U1196 and her sisters are prepared to die, J1178 bursts out that U1196 and the other "foreigners" belong to the same body, and that they should fight together because U1196 deserves to see the healthy body she helps create. J1178 calls U1196 "Older Sister," showing that she's fully accepted her, and U1196 is genuinely touched.
There is a chapter 0 special regarding the body of a 40-year-old woman who's been undergoing stress that's passing down to her immune cells, which are running ragged pursuing breast cancer. However, because this body undergoes regular breast cancer screenings that find and allow the removal of tumors too large for the immune cells to handle, this special is Lighter and Softer, with a red blood cell who loves serving the milk duct and an unusually kind NK cell.
