 This was mainly the result of the participation of AFIP staff as panel members and reference center heads in the International Histological Classification of Tumors (IHCT) series of the World Health Organization (WHO).WHO reference and collaborating centers were established at the AFIP in a number of subjects aimed at international standardization of tumor nomenclature, classification, and diagnostic criteria.AFIP staff contributed the largest number of IHCT panel members than any other institution.