TP53 and infection: We next assessed whether APC deficiency was associated with altered activation of the DDR upon infection with the genotoxic Salmonella. To this end, 1CT and 1CTA cells were infected with the MC1 TT strain, and the kinetics of expression of DNA damage sensor proteins (phospho‐KAP1 and γH2AX) and transducer effectors (phospho‐CHK2 and phospho‐p53 on Ser 15) were monitored over a period of 72 hr.