ALDH1A1 and lymphoma: Interestingly, ALDH1 activity was significantly higher (median %: 1.3, range 0.24–4.84; p = 0.0023, two-tailed Student’s t-test) in C91/III cells compared to the parental cell line (Figure S1), suggesting that their highly lymphomagenic activity might be associated with this subpopulation of lymphoma-initiating cells.