Pembrolizumab monotherapy, which enhances the immune response against tumor, demonstrated effective antitumor activity, clinically meaningful response, and acceptable safety parameters in primarily middle-aged man with metastatic cSCC, in spite the fact that the patient had an already immunity dysfunction since birth (Netherton syndrome in this case) due to uncertain mechanism, and also elevated IgE and eosinophils level due to seasonal allergy. The gene discussed is IGHE; the disease is Netherton syndrome.