APOD and schizophrenia: Notwithstanding, due to the majority of studies highlights lipids metabolism as generally observed affected pathway at schizophrenia, we assume that its relationship with the cholesterol metabolism (hsa04979) and associated signaling is the most essential reference point due to the interplay between APOM, carrying 9-cis-retinoic acid ligand, and APOD, affecting the RXR/PPAR receptors; both regulate the expression of numerous of apolipoproteins (Fig. 3).