TP53 and breast carcinoma: Another study showed that as many as 20% of tumors that retain the ability to become senescent in response to chemotherapy showed mutated TP53 [65], while still others indicated that TP53-dependent senescence was induced [66], as exemplified by the induction of senescence in TP53 wild-type MCF-7 breast cancer cells exposed to doxorubicin [62].