Consistently, we also found that in a commercially available cell line panel consisting of LoVo cells and 12 cell lines that harbor a range of mutations in PIK3CA present in tumor cells of cancer patients, PIK3CB-mutated LoVo cells were the most sensitive cells in the panel to TGX-221; in contrast to the cell lines with PIK3CA mutations, LoVo cells were the least sensitive to BYL-719-mediated inhibition of cell proliferation (data not shown). The gene discussed is PIK3CA; the disease is cancer.