This update of the RAPH blood group system (Hayes M. RAPH blood group system. Immunohematology 2014;30:6–10) reports no new alleles. The RAPH blood group system (International Society of Blood Transfusion system 25) consists of a single antigen (MER2) expressed on CD151, a member of the tetraspanin family of proteins. CD151 regulates interactions with laminin-binding integrins α3β1, α6β1, α6β4, and α7β1 and is expressed on red blood cells as well as many other tissues and cancer types. Lack of the RAPH protein is associated with nephropathy with pretibial epidermolysis bullosa and deafness.