This, together with the low levels of the H3R, suggests that cardiomyocytes do not express the H3R. Recently, Piera et al. [17] reported that myofibroblasts isolated from the scar region of the rat heart four weeks post-ischemia possess the H3R and could increase collagen production in response to H3R activation with imetit. The gene discussed is HRH3; the disease is ischemia.