BUB1 and cervical squamous intraepithelial neoplasia: A small fraction of CIN cancers are associated with dominant mutations in the human homologues of yeast spindle checkpoint genes BUB1 (Cahill et al, 1998; Imai et al, 1999; Gemma et al, 2000) and MAD2 (Li and Benezra, 1996; Cahill et al, 1999).