STAT3 and pulmonary arterial hypertension: Finally, while we focused on Hippo–YAP/TAZ signaling, MELK may also intersect with other PAH-relevant pathways, including PI3K–Akt–mTOR, ERK1/2–MAPK, and STAT3 signaling (Liu et al., 2023; Tian et al., 2021; Bisserier et al., 2021).