Among TIER1 hotspots, PIK3CA mutations were 39-fold more associated with ICC (p = 2.2 × 10−16, OR = 38.9, 95% CI = 16.3–92.7) compared to controls, while non-PIK3CA mutations were 6-fold more associated with ICC (p = 1.3 × 10−6, OR = 5.9, 95%CI = 2.9–12.2) compared to controls (Table 3). This evidence concerns the gene PIK3CA and intrahepatic cholangiocarcinoma.