PIK3CA and lung adenocarcinoma: Compared with KRAS HS, significantly lower HS values were observed for BRAF and PIK3CA. As copy‐number gains in wild‐type alleles are rare in BRAF and PIK3CA mutations of lung adenocarcinoma (Sasaki et al., 2015; Yamamoto et al., 2008), these results suggest that BRAF and PIK3CA mutations are more likely to occur in the subpopulation of tumor cells.