CTLA4 and cancer: Control group (n = 37): age, mean = 61, 65, n = 28 men and n = 9 women, types of cancers: urological (n = 16), gastrointestinal (n = 9), hepatobiliary (n = 5), head and neck (n = 3), bronchial (n = 3), gynecological (n = 0), squamous cell (n = 1), treatment: PD‐1/PD‐L1 monotherapy (n = 10), PD‐1/CTLA‐4 combination therapy (n = 4), PD‐1/PD‐L1 + tyrosin kinase inhibitor (n = 14), PD‐1/PD‐L1 + chemotherapy (n = 9).