RECK and ameloblastoma: RECK expression gradually significantly decreased in KCOT (87.5%), ameloblastoma (56.52%) and ameloblastic carcinoma (0%, P < 0.01), and was significantly higher in primary ameloblastoma (71.11%) than in recurrent ameloblastoma (29.17%, P < 0.01), but no significant difference was seen between histological types (Table 1).