PLCB1 and breast cancer: Given the importance of PI(4,5)P2 in multiple cellular processes, we were intrigued by the finding that transcriptomic profiling of MDA‐MB‐231 breast cancer cells and their in vivo‐selected highly metastatic derivative LM2 subline revealed two genes, PTPRN2 and PLCB1, that possess known enzymatic activity for PI(4,5)P2 to be both upregulated at the transcript and protein levels in LM2 cells (Figs 1A and B, and EV1A and B) (Minn et al, 2005; Tavazoie et al, 2008).