SPP1 and leukemia: Ghrelin was reported to attenuate myocardial calcification induced by nicotine and vitamin D3 via an increase and decrease in osteopontin and endothelin-1 expression, respectively, in the myocardium.53 The mechanism through which leukemia, the main cause of death in SAMP8 mice, was inhibited by treatment with rikkunshito remains clarified in relation to ghrelin.