PIK3CA and neoplasm: The simultaneous presence of two strong spatially close driver mutations is rare in a patient tumor; there are only 15 doublets belonging to the same cluster accumulated in EGFR, KRAS, PIK3CA, and TP53. However, some weak drivers are proximal to either a strong driver or another weak driver, as in the cases of mutations at positions R130/R173 in PTEN. Spatially close residues may form potent allosteric couples, which may enhance proliferation.