Briefly, syngeneic recipient mice were injected with Eμ-myc lymphoma cells carrying floxed Hdac1 and Hdac2 alleles as well as hormone-inducible cre (Hdac1F/F; Hdac2F/F; Actin-cre ER tg; Eμ-myc tg) and subsequently treated with 4-hydroxytamoxifen (4-OHT) to induce deletion of Hdac1 and Hdac2 specifically in transplanted tumor cells. The gene discussed is HDAC1; the disease is lymphoma.