Skin toxicities, such as rash, pruritus, vitiligo, palmar-plantar erythrodysasthesia (PPE), erythema, eczema, urticaria, dermatitis, dry skin, and maculopapular rash, were frequently observed in cancer patients treated with PD-1 or PD-L1 [3, 10, 11]. Here, PDCD1 is linked to cancer.