Since NB cells and MSCs share the expression of certain markers like CD90 and GD2, we performed qPCR testing on FACS-sorted MSCs from BMpos in order to: (i) ascertain that we can confidently discriminate between MSC and NB during FACS isolation and thereby (ii) demonstrate that the increase in MSC frequency is not caused by erroneously including NB cells in the analysis. Here, THY1 is linked to neuroblastoma.