This showed that while the recurrent coding-region mutations are still inconclusive for BRCA1-positive samples, PIK3CA H1047R, E545K, N345K, and E542K were consistently identified across all databases for BRCA1-negative samples and, therefore, may be used as common target neoantigens for the BRCA1-negative breast cancer vaccine. The gene discussed is PIK3CA; the disease is breast cancer.