PIK3CA and breast cancer: FXYD3 has been reported to be highly expressed in diverse cancer tissues and its aberrant up‐regulation contributed to the progression of breast cancer by activating PI3K‐AKT signalling.23, 24 Aberrantly activated PI3K‐AKT is frequently expressed in various cancers,40 in which the continuous activation of PI3K‐AKT contributes to the progression of cancer, e indicating a bad clinical outcome.26