MAP2K7 and myeloproliferative disorder: However, the two MEK/ERK dual inhibitors that we tested, AZD6244 and PD0325901 did synergize with a CI of 0.6 (Fig. 1C), which qualifies as a weak synergy by the Chou-Talalay method, suggesting that the MEK/ERK pathway does contribute to the cytokine-independent growth of MPN cells.