MK1775 is synergistic with Ara-C ex vivo. Percentage inhibition of relative cell number for the combination of Ara-C and MK1775 over Ara-C alone in primary AML, MDS, and CML patient samples. (A) Initial 4 (of 5) primary samples as described in the text. (B) AML and MDS primary samples. (C) CML primary samples. For panels B and C, the maximum percentage inhibition is shown for any concentration of MK1775 or Ara-C (darkly shaded bars) and for the greatest inhibition observed at or below 380nM MK1775 with any concentration of Ara-C (lightly shaded bars; see “MK1775 sensitizes primary AML, MDS, and CML specimens to Ara-C ex vivo” details).