PDCD1 and breast cancer: In certain tumor models, SKAP1 deficiency was shown to suppress the expression of programmed cell death 1 (PD‐1) in cytotoxic T cells to enhance antitumor immunity.[6] Intriguingly, apart from T‐cell lymphoma,[7] increased SKAP1 expression was recently observed in non‐hematologic cancers, such as colorectal[8] and gastric cancers.[9] In addition, genomic structural analyses identified a SKAP1 fusion gene expressed in breast cancer cells,[10] suggesting a potential role for SKAP1 in cancer cells.