PPDPF GI:13236524 pancreatic progenitor cell differentiation and proliferation factor homolog 1 maaipssgsl vathdyyrrr lgstssnssc sstecpgeai phppglpkad 50 51 pghwwasfff gkstlpfmat vlesaehsep pqasssmtac glardaprkq 100 101 pggqsstasa gpps