INPP4B and breast cancer: In conclusion, although this is a pilot discovery study and follow-ups with larger patient cohorts are required to further train and validate our classifier, our findings suggest that both INPP4B and CDK1 are promising alternative targets for anti-cancer therapy, as they exhibit a similar level of association with ER status and tumor grade as ERBB2 with HER2 status, which is already successfully targeted to treat HER2+ breast cancer patients.