Following the addition of (0.1, 0.5, 1 and 10 MK-1775 and BMN673 and their combinations), for 24, 48 and 72 h, the viability, i.e., the estimation of remaining live healthy cells in response to therapy of the cell population was estimated using WST-1 viability assay (Roche Diagnostics GmbH) as previously described in more detail (47 (link),48 (link)).