In an attempt to elucidate mechanisms triggered by the stromal BM microenvironment that could be modifying the activity of S63845 and venetoclax, we subsequently analyzed the expression of MCL-1 and BCL-2 anti-apoptotic proteins in MM.1S cells cultured for 48 h in direct contact with pMSCs isolated from four MM patients (Figure 1C). Here, MCL1 is linked to Miyoshi myopathy.