Interleukin-10 (IL-10), an immunoregulatory cytokine, has been proposed as a theoretical adjunct to PD-1/PD-L1 blockade to temper off-target inflammation while sustaining antitumor immunity; mechanistic and early clinical work with pegylated IL-10 (pegilodecakin) shows CD8+ T-cell activation and feasibility with anti-PD-1 therapy, yet randomized phase 2 trials in non-small-cell lung cancer did not improve efficacy and reported higher toxicity versus ICIs alone, so there is no guideline-endorsed prophylactic role (62, 63). This evidence concerns the gene CD274 and non-small cell lung carcinoma.