As the CD59/CD55‐deficient phenotype is measured in the human erythrocyte PIG‐A assay, it might be hypothesized that cisplatin‐induced GPI‐deficient PIG‐A mutant erythrocytes in cancer patients are under pressure for elimination by the complement system, as occurs in PNH patients. This evidence concerns the gene CD55 and paroxysmal nocturnal hemoglobinuria.