SP1 and cancer: In non-cancer cells, RARα/Sp1 enhances induction pyruvate dehydrogenase kinase 4 (PDK4), guanylyl cyclase/atrial natriuretic peptide receptor-A (Npr1), apelin and TNFα-inducible protein 3-interacting protein 1 (TNIP1) [126,127,128,129].