In addition, meta-analyses and clinical trials have shown that the use of PD-L1 and PD-1 inhibitors significantly increases the risk of liver toxicity [18], immune-related pneumonitis [19], thyroid dysfunction (especially hypothyroidism) [20], pruritus, fatigue, rash, and nausea (especially with combinations of anti-PD-L1 and anti-PD-1) [21]. This evidence concerns the gene PDCD1 and toxicity.