CASP3 and pulmonary arterial hypertension: The downregulated fork-head box O1 (FoxO1) and caspase 3 intensify the proliferation of PASMCs and the PA remodeling.256 PTX is an often utilized chemotherapeutical drug; nevertheless, a study revealed that PTX could upregulate FoxO1 and inhibit PASMC proliferation.256 A recent report by the same group indicated that co-delivery of FoxO1 stimulus PTX and pro-apoptosis protein caspase 3 to PASMCs could attenuate MCT-induced PAH model, using the similar co-delivery technique that the active protein was loaded onto PTX nanocrystals.256