Our analysis of the activation status of KIT in 17 KIT-positive GISTs by the detection of phosphorylated tyrosine residues shows that at least a fraction of KIT was activated in each tumour, even in the absence of gain-of-function mutation, consistent with previously published data (Rubin et al, 2001; Heinrich et al, 2003b; Antonescu et al, 2005). Here, KIT is linked to neoplasm.