VCAM1 and teratoma: At 4 weeks, teratomas were harvested and EGFP+ (teratoma-derived) skeletal myogenic progenitors, defined as lineage-negative (Lin−) (CD31− and CD45−, i.e., non-endothelial and non-hematopoietic, respectively), α7-integrin+, and VCAM-1+ (α7+ VCAM+), were isolated by fluorescence-activated cell sorting (FACS) (Figures 1A and S1A) (Chan et al., 2018).