CD274 and mesothelioma: TOP2A positivity, a marker of doxorubicin, etoposide and epirubicin response,19, 21 was associated with PD‐L1 expression in nonepithelial ovarian cancer (p = 0.029), soft tissue sarcoma (p < 0.001), cancer with unknown primary (p < 0.001), nonmelanoma skin cancer (p = 0.045), nonsmall cell lung cancer (p < 0.001), neuroendocrine tumors (p = 0.003), mesothelioma (p = 0.013), kidney cancer (p < 0.001), head and neck cancer (p = 0.001) and female genital tract malignancy (p < 0.001).