CYP11A1 and neoplasm: Inhibition of immune cell steroidogenesis by genetic deletion of the first and rate-limiting enzyme of the steroidogenesis pathway, Cyp11a1, in all immune cells, using Cyp11a1fl/fl;Vav1Cre mice, restricts TNBC tumour progression by reinstating anti-tumour immune responses in dendritic cells and T cells by impeding glucocorticoid signalling.