In the present study, although lung adenocarcinoma cells A549 also expressed AKR1B10, this effect was not significant due to the following reasons: 10 μM of ibrutinib exhibited almost 2-fold the inhibitory potency over recombinant AKR1C3 than that observed with AKR1B10, even when AKR1B10 had a 4.7-fold lower specific activity compared to that of daunorubicin [38]. This evidence concerns the gene AKR1C3 and lung adenocarcinoma.