TNFRSF1B and cardiac hypertrophy: (2) Importantly, direct addition of exogenous tmTNF-α into myocardial cell culture significantly alleviated ISO-induced cardiac hypertrophy and inflammatory cytokine production, and induced proliferation, rather than apoptosis in H9C2 cells, and the beneficial effects were entirely blocked by TNFR2 KO or/and KD; in contrast, addition of sTNF-α markedly exacerbated the pathological changes and induced apoptosis, and these effects were completely abolished by TNFR1 KO or/and KD.