Role of autophagy in Palb2-associated mammary tumor development. A, Kaplan-Meier survival curves showing mammary tumor development in Palb2-single and Palb2;Trp53-double conditional knockout mice in Becn1+/+ and Becn1+/− backgrounds. B, Autophagosomes observed in tumors from mice with indicated genotypes. Note that tumor #827 contains a Trp53 point mutation (Table 1), although it developed in Trp53-wild type mice. C, IHC analysis of autophagy substrate p62 in tumors arising from the 4 different genetic backgrounds as indicated. Tumors #751 and #163 still retained wild type Trp53, whereas #915 and #890 had acquired somatic mutations in Trp53 (Table 1). D, IHC analysis of cleaved caspase 3, a marker of apoptosis, in the same tumors as in C.