CYP2S1 and obesity due to melanocortin 4 receptor deficiency: Moreover, other identified markers of energy metabolism-related pathways may also provide clues about crosstalk between tumor and energy metabolism, including acetone degradation I (CYP19A1, CYP1B1, CYP2J2, CYP2S1, CYP4B1, and CYP4X1), fatty acid beta-oxidation III (ECI1, and EHHADH), ketogenesis pathway (ACAT2, BDH1, BDH2, and HMGCS2), and leptin signaling in obesity (FGFR4, JAK2, PDIA3, PLCB3, PLCH1, PRKACA, PRKACB, PRKAR2B, and PTPN11).