The General Medicine and Cancer Institutes Collaborative Access Team (GM/CA-CAT) at the Advanced Photon Source (APS) is a part of the Biosciences Division (BIO), Argonne National Laboratory (ANL).

The GM/CA CAT has been established by the National Institutes of Health's (NIH) National Institute of General Medical Sciences (NIGMS) and National Cancer Institute (NCI) to build and operate a national user facility for crystallographic structure determination of biological macromolecules by X-ray diffraction.