The Pathology Core serves three basic functions which include tumor procurement and banking, research immunohistochemistry and basic histology services. The Tissue Procurement and Banking Service provides research-driven access to and distribution of fresh or archived tumor tissue to investigators at the Center; priority is accorded to the needs of funded research studies. The frozen tissue repository of MSKCC provides the basis for the expression profiling and other array-based studies that may lead to better classification, prognostication, and therapeutic choices. Its ability to provide disease- and stagespecific tissue in response to protocol-driven studies is essential. Research immunohistochemistry is, performed on fresh frozen and formalin fixed tissue as well as cell lines as requested by investigators. Besides using established antibodies, the facility will optimize staining protocols for novel antibodies as well as determine their staining characteristics on tissues and cell lines. Basic histology services include cutting and staining of fresh frozen and formalin fixed, paraffin embedded tissues and cell lines, tissue microdissection for molecular analysis, and construction of tissue microarrays as well as digital capture of tissue microarray images for signal quantification.