ALDH1A2 and neoplasm: In this study, we first confirmed the enrichment of ALDH1A2 and ALDH1A3 expression during NB TICs selection in one PDX tumor (NB1), as well as in two distinct cell lines, the NB1-C cells derived from the NB1 PDX tumor, and/or the I-type SK-N-Be2c cell line.