PTEN and neoplasm: Down‐regulation of PTEN expression, via direct targeting by hypo‐EV delivered miR‐21, has been shown to promote the immunosuppressive functions of tumour associated macrophages (Ren et al., 2019) and myeloid‐derived suppressor cells (Guo et al., 2018; Li et al., 2019), likely leading to cancer progression.