TRPC1 and pulmonary arterial hypertension: However, TRPC1/4/5 channels have been implicated in various human diseases, including seizures (TRPC5 and TRPC1:C4) [75], fear-related behaviour (TRPC5) [76,77], severe pulmonary arterial hypertension (TRPC4) [78,79,80], heart failure (TRPC1/C4) [81], and chemotherapeutic resistance of cancers (TRPC5) [82,83].