Four studies have investigated the association between cellular proliferation in anal carcinoma as determined by the Ki-67/MiB1 index and clinical outcome (Table 6) (Allal et al, 1998; Grabenbauer et al, 1998; Indinnimeo et al, 2000b; Ajani et al, 2009). The gene discussed is MIB1; the disease is anal carcinoma.