The development of the eyelid requires coordinated processes of cell proliferation, morphology changes, migration and cell death. Map 3 k 1 is an important member of MAPK family and its protein, MEKK1, is a crucial cross-point in MAPK signal pathway. MEKK1-JNK signal pathway regulates actin filament formation and cell migration through enhancing the transcriptional activity of Ap-1.Moreover, MEKK1 has a possible interaction with HB-EGF/EGFR-ERK by c-jun. The Map 3 k 1 knockout mouse is defective in embryonic eyelid closure, and Map 3 k 1 mutant results in the postnatal corneal disease in mouse. Thus, study of Map 3 k 1 function provides a new perspective for human congenital eyelid defects and the corneal disease, and sheds the new light on early diagnosis, prevention, and therapy of this disease.