SPP1 and adenocarcinoma: Our conclusion differs from those arrived at by Zhang et al (2001), who observed a preferential OPN expression in squamous-cell carcinomas (OPN immunoreactivity in 68.8% of squamous-cell carcinomas vs 20.8% of adenocarcinomas), and from those of Shijubo et al (1999), who described a significantly worse prognosis of stage I adenocarcinomas as compared to other groups, but matches that of the Schneider group's study (Schneider et al, 2004).