. "Edited: Rothfels, K, 2012-05-16"^^ . "Reviewed: Ezzat, S, 2012-05-15"^^ . "Authored: Rothfels, K, 2012-02-09"^^ . "FGFR1-amplified lung cancer and breast cancer cells show strong phosphorylation of FGFR1 and do not show elevated levels of FGF ligand, suggesting that these receptors can undergo ligand-independent activation. Phosphorylation is enhanced in the presence of exogenous ligand, supporting the notion that overexpressed FGFR1 can be activated by both ligand- and ligand-independent pathways (Koziczak, 2004; Dutt, 2008; Weiss, 2010). The biochemical consequences of overexpression of FGFR1 in other cancer types remain to be determined (reviewed in Turner and Gross, 2010; Wesche, 2011."^^ . . . . . . . . . . "Ligand-independent phosphorylation of overexpressed FGFR1"^^ . "2.7.10"^^ . . . . . . .