MAP2K2 and breast cancer: In postmenopausal ER + BC, the CC genotype more frequently harbored alterations in APC (p < 0.01), CNAs in FGFR3, FOXA1, and MAP2K2, and fusion events involving PDCDC1 (the gene encoding PD-1) and BRAF (all p < 0.05 to ** p < 0.001) (Figure 3A).