Genes associated with PC1 included A2m, transcripts implicated in obesity and energy/lipid metabolism (Snhg11, Dhcr24, Ighm), FGF and WNT signaling (Shisa3, Lrg5), bone resoprtion (Car1), cellular senescence (Hist1h3e) and ECM binding/degradation (Hapln1, Itgb8, Fndc1), and transcripts associated with PC2 included genes implicated in innate immunity and inflammatory signaling (Ppbp, Epx, Trem1, Prg2, CD226), bone mineralization (Aspn), cell-matrix adhesion (Itgb3) and apoptosis (Bcl6) (Figure 3C). Here, TREM1 is linked to obesity due to melanocortin 4 receptor deficiency.