hAMSCs-H cultured in GBM CM remained negative for CD31, CD34, and CD45, while expressing high levels of CD73, CD90, and CD105, consistent with International Society for Cellular Therapy (ISCT) criteria for MSCs.2 However, although hAMSCs-N also remained negative for CD31, CD34, and CD45 while expressing high levels of CD90 and CD105, they did not express high levels of CD73, and thus did not meet strict ISCT flow cytometric criteria for MSCs (63.6%, high level defined as ≥AMS expression) (Figure 3f). This evidence concerns the gene PECAM1 and glioblastoma.