Meanwhile, 1,3,5,8-tetrahydroxyxanthone (17), 1,5,8-trihydroxy-3-methoxyxanthone (18), and 1,7-dihydroxy-3,8-dimethoxyxanthone (19) could reduce the expression of PI3K, p-Akt, and p-mTOR in a concentration-dependent manner in two CRC cell lines (Figure 7B–D). Here, PIK3CA is linked to colorectal carcinoma.