To investigate the sensitivity of human ALK+ ALCL cells towards HDAC inhibition, we used the class I HDACi Entinostat, which inhibits HDAC1, HDAC2, and HDAC3 (with respective IC50 values of 0.163, 0.396, and 0.605 μM) [34]. The gene discussed is HDAC2; the disease is anaplastic large cell lymphoma.