Given the small size (7%) of the MKK4-negative group (as expected, given the 5%-10% incidence of genetic loss in carcinomas), a Cox proportional hazards analysis was performed, adjusting for age, sex, and tumor stage.
Our data indicate that the loss of Mkk4 protein expression in pancreatic carcinomas may be more frequent than suggested by the rates of genetic inactivation alone and that MKK4 loss may contribute to disease progression.
Expression of the MKK4 transcript was easily detectable in all normal and benign tumour tissues and none of 102 primary carcinomas and cell lines showed an abnormal reduction in MKK4 expression.