A retrospective study of blood sample analysis in patients with stage IIIb-IV melanoma after three months of combined therapy with cetirizine and anti-PD-1 antibodies showed that combining anti-PD-1 mAb with cetirizine can significantly improve the progression-free survival (PFS) (28 vs. 15 months; 30 vs. 15 months in ICI-treated patients) and overall survival (OS) (36 vs. 23 months; 40 vs. 22 months in ICI-treated patients) of patients who had received other ICI treatments[25]. The gene discussed is PDCD1; the disease is melanoma.