Castle Biosciences, Inc. is a commercial-stage diagnostics company. The Company is focused on providing physicians and their patients with personalized, clinically actionable information to clinicians and their patients to inform treatment decisions and improve health outcomes. Its portfolio consists of tests for skin cancers, uveal melanoma, Barretts esophagus and mental health conditions. Its products include DecisionDx-Melanoma, DecisionDx-SCC, MyPath Melanoma, TissueCypher, and DecisionDx-UM, IDgenetix. DecisionDx-Melanoma is a risk stratification gene expression profile (GEP) test that predicts the risk of metastasis, or recurrence, for patients diagnosed with invasive cutaneous melanoma (CM), a deadly skin cancer. MyPath Melanoma is GEP test offering for patients with difficult-to-diagnose melanocytic lesions. IDgenetix is pharmacogenomics (PGx) test that helps to guide optimal drug treatment for patients diagnosed with major depressive disorder, bipolar disorder, and other.