Dr Katherine Hoardley from the University of North Carolina and colleagues presented the mutational analysis of CALGB 40601 (Alliance), a neoadjuvant phase III trial of weekly paclitaxel (T) and trastuzumab (H) with or without lapatinib (L) for HER-2-positive breast cancer, in which they identified the presence of a TP53 mutation was significantly associated with achieving pCR (59% compared to 28% in wild type; OR = 3.7, P < 0.0001) which did not vary by treatment arm. This evidence concerns the gene TP53 and breast cancer.