PLCB1 and major depressive disorder: We also report no variance in PLCB1 protein levels in BA24 in these subjects, a region previously shown to be impacted in MDD.23 Abnormalities in PLCB1 levels could therefore play a role in Sz pathophysiology, and represent a biological marker for Sz as well as those with the disorder who are at risk of suicide dependent on the isoform measured.