To sustain multiple myeloma (MM) plasma cell killing, DNA damage response (DDR) was triggered via phosphorylation of ATM/ATR kinases, CHK1/2, CDK1/2, and H2AX in MM cells by MEDI2228, a novel BCMA antibody-drug conjugate (ADC) delivering the DNA cross-linking PBD dimer tesirine in MM cells regardless of drug resistance and p53 status (20). Here, CDK1 is linked to Miyoshi myopathy.