CD274 and breast cancer: Regardless of ICIs (combined with chemotherapy) being approved for patients with PD-L1-positive mTNBC, it would be of clinical interest to investigate 1) whether patients with other breast cancer subtypes and TMB-H, such as estrogen receptor-positive tumors, could also benefit from ICIs and 2) whether patients with TMB-H PD-L1-positive mTNBC could be treated solely with immunotherapy and be spared from chemotherapy.