The B-cell developmental stage of arrest impacts InO sensitivity in B-ALL samples. Escherich et al used bulk RNA sequencing and a gene expression reference for normal B lymphopoiesis to infer the relative contribution of transformed B-cell developmental stages to individual B-ALL samples. The relative proportion of more immature Pre-pro B cells increased in cases with Ino resistance, while the relative proportion of more mature pro B cells decreases. The InO target antigen CD22 is a direct target for transcriptional regulation by EBF1, which are both initiated at the Pre-pro B stage of normal B lymphopoiesis (CD22 and EBF1 expression taken from https://scminer.stjude.org).7 Professional illustration by Patrick Lane, ScEYEnce Studios.
