To investigate the role of PYCR enzymes on MM viability in vitro, we measured the RNA and protein expression of both enzymes on five HMCL originating from different MM subclasses (MMSET: OPM-2, MMSET/FGFR3: LP-1, cMAF: RPMI-8226, JJN-3 and IL-6 dependent cell line ANBL-6) and one stromal cell line HS-5 (Fig. 2A-B). This evidence concerns the gene PYCR1 and Miyoshi myopathy.