TP53 and cytomegalovirus infection: To evaluate whether HCMV infection is associated with possible conformational changes in the p53 protein that affect its susceptibility to calpain‐mediated cleavage and generation of the observed p53 fragments, we extracted nuclear proteins from mock‐ or HCMV‐infected cells and exposed them to exogenous purified human μ‐ or m‐calpain.