ALDH1A1 and neoplasm: ALDH1A1 inhibition had a weak effect on the production of immune-stimulating cytokines (IFNγ: 1.72 and IL-12: 1.34 fold change vs. control cells, Supplementary Figure S5e) and, in particular, the blocking of RAR and RXR nuclear receptors failed to decrease PD-L1 expression in 3A1high cells (Supplementary Figure S5f), indicating the existence of a selective link between ALDH3A1-dependent redox metabolism and intrinsic immunity in our tumor models.