These changes in apoptosis and proliferation of azacitidine-exposed cells were validated at the protein level by IHC of tumor samples (spleen) of TFHL-PDX, which showed a significant increase in p53 and p21 expression in azacitidine-treated samples (Fig. 5E), as well as that of cleaved-caspase 3 as an indicator of apoptosis (Fig. S8B), whereas the expression of BCL2 and MIB1/Ki67 was downregulated, indicating lower proliferation in azacitidine-treated mice (Fig. S8C). Here, MIB1 is linked to neoplasm.