PIK3CA and breast cancer: In contrast, PIK3CA displayed the highest mutation rate in BC-ImM (BC-ImH (28.2%) versus BC-ImM (41.3%) versus BC-ImL (28.1%)), while GATA3 had the highest mutation rate in BC-ImL (BC-ImH (5.4%) versus BC-ImM (10.8%) versus BC-ImL (13.1%)).