INPP4B and neoplasm: Proteins that contribute most strongly to proteotype-based classification include inositol polyphosphate-4-phosphatase, type II (INPP4B), cyclin-dependent kinase 1 (CDK1), and receptor tyrosine kinase 2 (ERBB2) are associated with estrogen receptor (ER) status, HER2 status tumor, and grade status.