In the first study, previously treated patients with unresectable stage III or IV melanoma were randomized to receive ipilimumab 3 mg/kg every 3 weeks for four cycles in combination with the experimental glycoprotein 100 (gp100) peptide vaccine (n = 403), ipilimumab 3 mg/kg every 3 weeks for four cycles alone (n = 137), or gp100 alone (n = 136) [16]. Here, PMEL is linked to melanoma.