Although cetuximab skin toxicity, with acneiform rash being the principal clinical manifestation, has been extensively described in mCRC, there is poor evidence regarding anti PD-L1 immune-related skin toxicity in the same setting, considering that, unfortunately, only a few patients with an MSI tumor (almost 5%) could really benefit from CPI treatment [17,18,19,20,21,26]. The gene discussed is CD274; the disease is neoplasm.