PPP2R5D and bipolar disorder: Six genes (i.e., GYS1, HSP90B1, NFKBIE, PPP2R5D, RRAS, and TP53) were downregulated by TPM in this pathway, and HSP90B1, which encodes an endoplasmic reticulum chaperone gene, is altered in the postmortem brain of bipolar disorder patients (73), and is associated with bipolar disorder (74) and schizophrenia (75–78).