BDNF and cancer: The mitogen-activated protein kinase kinase (MEK) and its downstream signaling extracellular signal-regulated kinase (ERK) have been implicated in cancer progression processes such as metastasis, angiogenesis or lymphangiogenesis.21, 22, 23 We therefore examined whether the MEK/ERK pathway is involved in BDNF-mediated VEGF-C expression and lymphangiogenesis.