In ovarian cancer, expression of p16INK4a and pRb has been investigated in various studies using immunohistochemistry (Dong et al, 1997a, 1997b; Niemann et al, 1998; Kusume et al, 1999; Sui et al, 2000; Milde-Langosch et al, 2003; Raspollini et al, 2004; Hashiguchi et al, 2004). The gene discussed is RB1; the disease is ovarian cancer.