B2M and infection: With regards to β2-microglobulin-dependent immune responses, the enhanced susceptibility of B2m−/− mice to diverse pathogens such as Trypanosoma cruzi, Listeria monocytogenes, Chlamydia trachomatis, Mycobacterium tuberculosis and Klebsiella pneumoniae[66]–[70] has been used to demonstrate a requirement for MHC I-restricted T cells in protection against infection.