TNFRSF1A and schizophrenia: However, reports have shown shared cell death–related transcriptional expression between schizophrenia and bipolar disorder (75), including increased levels of TNFR1, TWEAKR, and FAS in serum (36,58,59,76, 77, 78), the frontal cortex (39,40,79), and the hippocampus (42).