CD74 and atherosclerosis: The invariant chain (CD74) of the major histocompatibility class II complex (MHCII), another substrate of SPPL2a, appears to be connected to the formation of atherosclerosis, CD74 has been validated to undergo RIP in vivo being initially shedded by serine or cysteine proteases, releasing the CD74 soluble ectodomain (CD74 ECD).