Thirdly, although we revealed that the anti-PD-1 therapy induced the expression of S100A1 in patients with breast cancer and that plasma S100A1 expression was elevated post-treatment compared with pretreatment in lung cancer patients with SD/PD, the relationship of S100A1 with the acquired resistance to ICIs needs to be analyzed. The gene discussed is PDCD1; the disease is breast carcinoma.