We first generated a murine PDX model of CDK7-overexpressing ICC (PDX0044) (Figure ​Figure77A). Once the xenografts reached a volume of 50-100 mm3, the tumor-bearing mice were randomly divided into two groups, and then intraperitoneally injected with either PBS or THZ1 (10 mg/kg) twice a day for 17 days. THZ1 treatment significantly reduced the tumor volume and weight (Figure ​Figure77B-D), without eliciting detectable toxic effects.