A study on 45 Japanese patients with advanced, unresectable malignant melanoma who received PD1 inhibitor therapy showed that a baseline absolute eosinophil count of >240/μL and relative eosinophil count at one month post treatment of >3.2% were associated with endocrine irAEs (OR 7.0; 95% CI 1.50–32.72; p = 0.013 and OR 5.11; 95% CI 1.23–21.28; p = 0.025, respectively) [43]. This evidence concerns the gene PDCD1 and melanoma.