“…EPCs are another group of important stem cells; they exhibit strong angiogenesis potential and play a key role in vasculogenesis and angiogenesis (Chong et al, 2016). EPCs have been used effectively to treat hindlimb ischemia (Flex et al, 2016;Yu et al, 2015), stroke (Bai et al, 2015;Li et al, 2015), diabetic ulcer (Barcelos et al, 2009;Tam et al, 2015), and myocardial infarction (Mehmood et al, 2015;Sheng et al, 2015). However, the greatest limitation of EPC-based transplantation is the scarcity of EPCs; unlike other stem cells, EPCs exist in umbilical cord blood (Finney et al, 2006;Lin et al, 2011;Moon et al, 2013;Phuc et al, 2012), bone marrow (Ii, 2010) and peripheral blood (Donndorf et al, 2015), with extremely low numbers, and have slow proliferation in vitro.…”