According to the PGS catalog, breast cancer is the disease with the highest number of PRS records deposited in the database (n = 117), with a total of 90 records for the “breast carcinoma” index and 17 PRS records developed for specific clinical subtypes of breast cancer (e.g., positive estrogen receptor, negative estrogen receptor, HER2 positive, HER2 negative, Luminal A, Luminal B, and triple-negative breast cancer). The gene discussed is ERBB2; the disease is breast cancer.