It is also in agreement with the clinical observation that the FU- and IRI-based combination therapy is effective in patients pretreated with FU (Andre et al, 1999) and whose tumours are generally characterised by increased levels of TS (Wong et al, 2001) as well as with our results obtained in three patients previously treated with FU-based adjuvant chemotherapy who achieved partial response with this modified FU/IRI regimen. Here, TYMS is linked to neoplasm.