MAPK1 and infection: Furthermore, a differential regulation of mitogen-activated protein kinases (MAPK) by wildtype and capsule-deficient N. meningitidis serogroup B strains could be demonstrated in HIBCPP cells, wherein N. meningitidis wildtype strains required active extracellular signal-regulated kinases (Erk1/2) and p38 pathways for infection, however, the invasion by the capsule-deficient mutant was independent of Erk1/2 and of p38 activity (Herold et al., 2021a).