Project Summary – PDX Core B The PDX Core provides major resources to the program investigators, including melanoma PDX, melanoma cell lines and 3D models such as organoids, spheres, and spheroids, to explore new therapies. Our melanoma PDX pre-clinical platform encompasses >500 different tumors representing all clinical, biologic, and genetic groups of the disease. The primary focus of the PDX Core is to establish, bank and distribuite new PDX and PDX-derived models. The PDX Core also coordinates the characterization the pre-clinical melanoma models at at the biological (e.g. growth and metastasis) and molecular (e.g. DNA- and RNA-sequencing, and protein expression) levels. The core maintains a master cell bank, conducts quality control of specimens and derived models and monitors for mouse pathogens. The core is also the central facilitator for exchanging PDX within the PDXNet and coordinates collaborations with other investigators within the program, the overall PDXNet and outside scientists. The core coordinates data storage, data sharing and distribution to other investigators within the program. The PDX Core is available to train investigators of the program in all biological assays and models. Overall, this core will provide efficient and high-quality service to all investigators within this PDTC. The PDX Core is also available to assist investigators withinPDXNet and collaborators as requested. 1