No abstract

FRS2K K and FRS2L L, two members of the FRS2 family of docking proteins, become tyrosine phosphorylated in response to ¢broblast growth factor (FGF) or nerve growth factor (NGF) stimulation. Tyrosine phosphorylated FRS2K K serves as a platform for the recruitment of multiple signaling proteins for activation of the Ras-mitogen-activated protein (MAP) kinase signaling cascade. We report that Frs2K K and Frs2L L have distinct spatio-temporal expression patterns in mouse embryos. We further show that FRS2L L can compensate for the loss of FRS2K K for activation of MAP kinase when expressed in ¢broblasts from Frs2K K 3 3/ /3 3 mouse embryos. We propose that the FRS2 family proteins have distinct roles in vivo through activation of common signaling proteins including MAP kinase.

If CT colonography shows no abnormality, follow-up screening in 5 years is recommended. If CT colonography detects a lesion smaller than 5 mm, follow-up imaging in 3-5 years is recommended. If CT colonography detects a lesion measuring 6 mm or more, endoscopy and polypectomy should be offered unless contraindicated.