FHIT and in situ carcinoma: In a somewhat smaller study that included CIS and dysplasia in sections of 75 ESCs, Fhit protein was reduced, relative to adjacent normal mucosa, in 89% of invasive ESCs, 68% of CIS lesions and 43.5% of dysplastic lesions, so that Fhit loss was associated with progressive ‘increases in severity of histopathological changes’ (Kitamura et al, 2001).