TWIST1 and medical procedure: This effect was more apparent when we examined the expression of these 2 proteins amongst lymph node negative patients where individuals with co-expression of TWIST1 and ZEB2 are 3.8 times more likely to have a poor prognosis compared to those with the expression of either one or neither of the proteins indicating that the co-expression of these 2 markers is an independent prognostic factor for identifying aggressive disease particularly amongst lymph node negative patients.