PIK3CA and breast carcinoma: To investigate if LINC00520 plays a broader role in transformation we turned to an orthogonal model using MCF10A mammary epithelial cells expressing oncogenic mutants of PIK3CA. The PI3K pathway is frequently hyperactivated in breast cancer mainly due to recurrent somatic mutations in PIK3CA, the gene that encodes the p110α catalytic subunit of PI3K, or via loss of the tumor suppressor Phosphatase and Tensin Homolog (PTEN) [19].