ETC-206 inhibits eIF4E phosphorylation in HeLa cell line with an IC50 of 321 nM. The anti-proliferative effects of ETC-206 are assessed in vitro, using CellTiter-Glo viability assay against 25 hematological cancer cell lines including the K562 cell line that overexpresses eIF4E (K562 o/e eIF4E). The IC50s are 1.71 μM, 3.36 μM, 3.70 μM, 4.81 μM, 5.13 μM, 5.05 μM, 6.70 μM, 9.76 μM, and 48.8 μM for SU-DHL-6, GK-5, MC 116, P3HR-1, DOHH2, MPC-11, Ramos.2G6.4C10, AHH-1, and K562 o/e eIF4E cells, respectively.