Roles of JAK2, ERK, and EGFR in E2- and E2+GH-stimulated proliferation. T47D cells were treated for 5 days with E2, GH, or both in the presence of vehicle [dimethylsulfoxide (DMSO)] or inhibitors for JAK2 (AZD1480, 1 μM) (A), MEK (U0126, 10 μM) (B), or EGFR (AG1478, 15 μM) (C). Proliferation was determined by the DNA assay. Bars with different letters are significantly different (P < .05).