Castle Biosciences is a company that provides diagnostic and prognostic testing services for dermatological cancers. Its lead product, DecisionDx-Melanoma, is a multi-gene expression profile test that identifies the risk of metastasis for invasive cutaneous melanoma patients. The company also offers other proprietary tests such as DecisionDx-UM and DecisionDx-SCC that predict the risk of metastasis for uveal melanoma and squamous cell carcinoma patients, respectively.