CD4 and cancer: Certain tumours have been found to induce the differentiation of naive peripheral CD4+ T cells into CD4+ CD25+ regulatory T cells via TGF‐β secretion,29, 30, 31 whereas other studies have found that the release of TNF‐α, interleukin (IL)‐1β, and IFN‐γ is elevated in certain cancer types, including in colon cancer upon interaction with lymphocytes.32 The mechanisms whereby TGFβ2 governs tumour progression and immune cell infiltration in GC, however, remain unclear.