In addition, PLA2G7 gene expression in peripheral blood might be able to predict the response to immunotherapy among melanoma patients, in combination with the expression of three additional genes including cathepsin D (CTSD), thioredoxin reductase 1 (TXNRD1), and interleukin 1 receptor‐associated kinase 3 (IRAK3). The gene discussed is CTSD; the disease is melanoma.