In a retrospective study of 193 patients with advanced ALM (nail = 70, palm and sole = 123) treated with anti-PD-1 antibody, the objective response rate was significantly lower in the nail unit (8.6%) compared to in the palm or sole (21.1%) (p = 0.026); median overall survival was also significantly shorter in nail patients (12.8 vs. 22.3 months, p = 0.03) [70]. The gene discussed is PDCD1; the disease is acral lentiginous melanoma.