In addition, MM cells are known to release the parathyroid hormone-related protein (PTHrP), which binds its receptor in MSCs and OBs, inducing the expression of the transcriptional repressor E4BP4; the latter indirectly inhibits the expression of Runx2 and Osterix through the transcriptional inhibition of cyclooxygenase 2 (COX-2) [160]. The gene discussed is PTGS2; the disease is Miyoshi myopathy.