CSPG4 and sarcoma: Coupled with the evidence that pericytes have been proposed as the identity of MSCs in normal tissues (Caplan, 2008; Crisan et al., 2008) and some sarcomas share features of pericytes, such as expression of NG2 (CSPG4) and CD146 (MCAM) (Benassi et al., 2009; Wei et al., 2015), we set out to address whether Pdgfrb-Cre and Cdh5-CreERT2 mice could be used to generate a model of angiosarcoma.