AXIN2 and obesity due to melanocortin 4 receptor deficiency: In addition, the qRT-PCR results showed that the reduced β-catenin in the nucleus of KO cells caused a change in the transcription level of its downstream genes and thus may affect obesity-related genes via different signaling pathways (Fig. 4G): the β-catenin target genes (such as c-Myc, Lef1, Ppard, Mmp7, and Axin2) decreased, and some of the obesity-related genes (such as Fabp4, Srebf, Cebpα, Seipin, and Ppar-γ) increased.