Immune: A Journey Into the Mysterious System That Keeps You Alive

by Philipp Dettmer

about 30% of people happen to have a second spleen that is tiny but will grow and take over the job if the first one is removed.

Before we move on, here is a really interesting fact: The genes that are responsible for the MHC molecules are the most diverse genes in the human gene pool, leading to a huge variety of MHC molecules between individuals. Of all the things that are different between humans, why are the MHC molecules so unique to every person? Well, different types of MHC are better or worse at presenting antigens from different enemies, like one type might be especially good at presenting a specific virus antigen while another type could be great at presenting a bacteria antigen. For humans as a species this is enormously beneficial because it makes it really hard for a single pathogen to wipe us out.

Kids who overcome a measles infection have a higher chance of getting other diseases afterwards because the measles virus kills Memory Cells.