The expression of TrkA is considered a favourable prognostic factor in several types of cancer (Kramer et al, 1996; Combaret et al, 1997; Descamps et al, 2001a), whereas activation of TrkA by phosphorylation correlates with a poorer clinical outcome in serous ovarian carcinoma (Davidson et al, 2003). This evidence concerns the gene NTRK1 and cancer.