STING1 and neoplasm: STING activity has been reported to promote the recruitment and/or induction of immune-suppressive myeloid-derived suppressor cell (MDSC) [35, 151–153] and regulatory T cell (Treg) [33, 154] populations, as well as the polarisation of monocytes to immune-suppressive ‘M2-like’ tumour-associated macrophages [155, 156].