GH rapidly up-regulates IEGs in a JAK2-, EGFR-, and ERK-dependent manner. A, T47D cells were treated with GH for up to 6 hours. Expression of IEGs was examined by QPCR. Data are presented as a heat map with the highest levels of expression for each gene in red and the lowest levels in green. B, GH-induced expression of IEGs was examined after pretreatment with inhibitors for EGFR (AG1478), MEK (U0126), or JAK2 (AZD1480).