FABP5 and cancer: A recent study linking LCFA to PPARβ/δ showed that LCFA binds FABP5 from the cytoplasm to nuclear PPARβ/δ and replaces endogenous ligands and retinoic acid conduction, where SLCFAs inhibit the FABP5-PPARβ/δ pathway to inhibit cancer and ULCFAs activate the FABP5-PPARβ/δ pathway to increase cancer cell proliferation (Hardy et al., 2000; Li et al., 2011; Hodge et al., 2015; Levi et al., 2015).