“…This gradient, in fact, attracts immune cells toward the wound edges. In addition, a redox sensor has been identified in the leading edge of neutrophils (Wittmann et al, 2012;Yoo et al, 2011Yoo et al, , 2012 and topical application of low doses of H 2 O 2 enhances wound closure in mice (Loo et al, 2012). Importantly, ROS are required for the regeneration of planarian head and tail (Pirotte et al, 2015), zebrafish caudal fin (Gauron et al, 2013) and heart (Han et al, 2014), Xenopus tadpole tail (Love et al, 2013), and gecko tail (Zhang et al, 2016).…”