Castle Biosciences, Inc., a commercial-stage diagnostics company, focuses to provide diagnostic and prognostic testing services for dermatological cancers. Its lead product is DecisionDx-Melanoma, a multi-gene expression profile (GEP) test to identify the risk of metastasis for patients diagnosed with invasive cutaneous melanoma. The company also offers DecisionDx-UM test, a proprietary GEP test that predicts the risk of metastasis for patients with uveal melanoma, a rare eye cancer; DecisionDx-SCC, a proprietary 40-gene expression profile test that uses an individual patient's tumor biology to predict individual risk of squamous cell carcinoma metastasis for patients with one or more risk factors; and DecisionDx DiffDx-Melanoma and myPath Melanoma, a proprietary GEP test to diagnose suspicious pigmented lesions. It offers test services through physicians and their patients. The company was founded in 2007 and is headquartered in Friendswood, Texas.