MDK and gastrointestinal stromal tumor: Immunohistochemical studies revealed MK protein expression in other carcinomas, including oral carcinoma (Ruan et al, 2007), oesophageal carcinoma (Ren and Zhang, 2006), gastrointestinal stromal tumours (Kaifi et al, 2007), liver carcinoma (Kato et al, 2000b), lung carcinoma (Sakitani et al, 1999), thyroid carcinoma (Kato et al, 2000a), and prostate carcinoma (Konishi et al, 1999).