Overexpression of PYCR1 and PYCR2 mRNA was shown to be associated with worse overall survival in patients with MM, and in vitro studies identified that pargyline, a selective monoamine oxidase B inhibitor that inhibits PYCR1, worked synergistically with bortezomib in inducing apoptosis in the MMCL RPMI-8226 [41]. Here, PYCR1 is linked to Miyoshi myopathy.