Met protein expression by immunohistochemistry in oral leukoplakia and time to oral cancer in patients with oral leukoplakia. Sections were immunostained with a total Met-specific antibody. Representative sections with no (A), low (B), or high (C) expression levels are shown. Black scale bar = 200 µm. D) The association of Met protein expression levels with time to oral cancer development was evaluated using a Kaplan-Meier curve. Statistical significance was given by the two-sided log-rank test. E/N = number of events and number of patients.