To address the insensitivity of colposcopy and the heterogeneity of cervical disease, NCI launched the NCI-Oklahoma Biopsy Study. In this study, investigators analyzed the increased accuracy in finding small cervical intraepithelial neoplasia grade 3 (CIN 3) lesions by taking multiple biopsies in a highly-standardized manner. They are using the improved understanding of cervical disease to better analyze the transition from human papillomavirus (HPV) infection that is likely to clear, to CIN3 that is a true cancer precursor. The design and initial results of the Biopsy Study have spurred the interest of many international groups. NCI is now collaborating with two centers in the Netherlands and in Spain that have adopted the Biopsy Study protocol to compare the incremental benefit of multiple biopsies at different clinical sites and to increase the power to study the clonality of cervical lesions. Recruitment in Voorburg, The Netherlands, and Barcelona, Spain is still ongoing with a combined accrual target of about 600 women.