Deletion of p53 in MM is more common in later stages of subclonal evolution, suggesting it may play a role in disease progression in affected patients.36 p53 mutation or deletion (including del [17p]) continues to be an indicator of high risk for relapsed/refractory disease, and post‐autologous stem cell transplant patients with p53 deletion have significantly worse survival.37 OTS514 treatment results in potent killing of 8 HMCLs carrying p53 mutations or deletions, including clear dose‐dependent p27 activation in p53‐null KMS11 cells. This evidence concerns the gene CDKN1B and Miyoshi myopathy.