ULBP2 and acute myeloid leukemia: Furthermore, treatment of AML cells with the LSD1 inhibitor tranylcypromine (2-PCPA) hydrochloride was able to upregulate expression of ULBP2/5/6, leading to increased susceptibility to NK cell-mediated killing, both in vitro and in vivo (138) (Figure 1 and Table 2).