CD274 and gastrointestinal stromal tumor: ERCC1 negativity, a marker of platinum response,29, 30 was associated with PD‐L1 expression in GIST tumors (p = 0.032), whereas ERCC1 positivity was associated with PD‐L1 expression in glioblastoma (p = 0.030), female genital tract malignancies (p < 0.001) and esophageal tumors (p = 0.010).