DecisionDx-UM is a prognostic test that accurately determines the metastatic risk associated with ocular melanoma tumors of the eye. Ocular melanoma is a term commonly used to describe tumors of the uveal tract such as uveal melanoma, choroidal melanoma, ciliary body melanoma, and iris melanoma. The DecisionDx-UM test was clinically validated on these tumors of the uveal tract. DecisionDx-UM assesses the gene expression profile (GEP) of a subset of genes which are differentially expressed in primary tumor cells compared to cells that have undergone transformation to a metastatic phenotype. The test classifies tumors as: Class 1A (low metastatic risk), Class 1B (long-term metastatic risk), Class 2 (immediate, high metastatic risk). Also referred to as the gene expression profile, the test has been directly compared to all other clinical and pathological factors, such as chromosome 3 status (monosomy 3), cytopathology and tumor size and the DecisionDx-UM test was shown to be more accurate than these other factors. The DecisionDx-UM test has become standard of care in the majority of ocular oncology centers in the U.S. and is recommended by the American Joint Committee on Cancer (AJCC). The AJCC recommends this testing for all patients with a diagnosis of uveal melanoma as the results are ‘clinically significant’. Accurate results are achieved using both fine needle aspirate biopsies (FNAB) or formalin fixed, paraffin embedded (FFPE) tumor tissue. The prognostic information provided by DecisionDx-UM helps physicians and their patients make individualized decisions about the surveillance and therapeutic options that are most appropriate. The DecisionDx-UM test was exclusively licensed from Washington University in St. Louis and is only available through Castle Biosciences, Incorporated. Uveal Melanoma While rare, uveal melanoma (ocular melanoma) is the most common form of eye cancer and the second most common form of melanoma. Uveal melanoma tumors arise in the uveal tract of the eye which includes the iris, ciliary body, and choroid. Treatment for the primary eye tumor consists of eye-sparing therapy (plaque radiotherapy or proton beam irradiation) or eye removal (enucleation). Both are highly effective with ‘cure’ rates above 90%. However, as has been well documented in multiple publications including the Collaborative Ocular Melanoma Study (COMS), in nearly 50% of patients the melanoma has likely already metastasized by the time the primary eye tumor has been diagnosed and treated. The majority of these metastases are microscopic and clinically undetectable at the time of primary tumor diagnosis. Unfortunately, many of the