CD4 and neoplasm: Allard et al. reported that in response to conditions typically occurring in neoplastic disease, such as hypoxia, various cells in the tumour microenvironment acquire adenosine-generating capabilities; these include cancer cells, endothelial cells, CAFs, CD4+CD25+Foxp3+ Tregs, Tr1 cells, Th17 cells, γδ T cells, NK cells, invariant cells (i)NKT, effector and memory T cells, B regulatory cells (Breg), myeloid-derived suppressor cells (MDSC), macrophages and neutrophils.