KIT and myocardial infarction: Of note, transthoracic Doppler echocardiography showed that implantation of either hHVS alone or c-kit+ cell-seeded hHVS onto infarcted myocardium significantly increased ejection fraction (EF; from 25.3% to 38.3% or to 59%) and fractional shortening (FS; from 12.3% to 18.7% or to 30.4%), respectively, on day 28 post MI/implantation (Fig. 5; Supplementary Table 1).