Patient #35 had an infiltrating lobular carcinoma luminal A PT which moved to a luminal B ovarian metastasis 2 years after diagnosis, with shared mutations in PIK3CA, ARID1A, and CDH1. The ovarian metastasis harbored no less than 8 different mutations, of whom 5 were M restricted, in MAP3K1, ROS1, LAMA2, INPP4B, and PGR. Only 5 patients in the ESOPE cohort had a lobular carcinoma, precluding further specific analyses. Here, MAP3K1 is linked to breast lobular carcinoma.