ASCL1 and Borderline personality disorder: The protein levels of MASH1 (Figure 2B.2), also known as Ascl1, that is expressed in transit-amplifying progenitors with a limited capacity for expansive proliferation (11), showed a significant decrease in BPD compared with control (p=0.005) and MDD (p=0.004; F=2,32 = 8.45, p=0.001) groups.