Castle Biosciences, Inc., a molecular diagnostics company, provides testing solutions for the diagnosis and treatment of dermatologic cancers, Barrett's esophagus, uveal melanoma, and mental health conditions. It offers DecisionDx-Melanoma, a risk stratification gene expression profile (GEP) test to identify the risk of metastasis for patients diagnosed with invasive cutaneous melanoma; DecisionDx-SCC, a proprietary risk stratification GEP test for patients with cutaneous squamous cell carcinoma; MyPath Melanoma, a test used for patients with difficult-to-diagnose melanocytic lesions; and TissueCypher, a spatial omics test to predict future development of high-grade dysplasia and/or esophageal cancer in patients with non-dysplastic, indefinite dysplasia, or low-grade dysplasia Barrett's esophagus. In addition, the company provides DecisionDx-UM test, a proprietary risk stratification GEP test that predicts the risk of metastasis for patients with uveal melanoma; and IDgenetix, a pharmacogenomic test that helps guide drug treatment for major depressive disorder, schizophrenia, bipolar disorder, anxiety disorders, social phobia, obsessive-compulsive personality disorder, post-traumatic stress disorder, and attention deficit hyperactivity disorder. It offers its products to skin cancer, gastroenterology, and mental health markets. The company was incorporated in 2007 and is headquartered in Friendswood, Texas.