While in previous studies proliferation of PASMCs in TRPC1−/− and TRPC1/6−/− mice was reduced (Malczyk et al., 2013), contradictory findings investigating TRPC6 exist: although it seems that knockdown of TRPC6 in IPAH patients led to a reduced proliferation of PASMCs (Yu et al., 2004) TRPC6 is not involved in PASMC proliferation in mice (Malczyk et al., 2013). This evidence concerns the gene TRPC6 and idiopathic pulmonary arterial hypertension.