CD4 and neoplasm: Transforming growth factor beta (TGFβ) is produced by many lung adenocarcinoma (ADC) cell lines and it induces immunosuppression in its microenvironment,2 inhibiting the host immune response by activating forkhead box P3 (Foxp3) transcription factor in naive CD4+ T cells, thus imprinting the T regulatory (Treg) phenotype at the cost of a T helper type 1 (Th1)–interferon-gamma (IFNγ)-dominated anti-tumour immunoresponse.7