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). The gene discussed is CYP4B1; the disease is obesity due to melanocortin 4 receptor deficiency.