MKI67 and neoplasm: Recent studies have reported numerous biomarkers (e.g., tumor size, node status, Ki-67, HER2) and imaging-based metrics (e.g., magnetic resonance imaging [MRI] and positron emission tomography) for the prediction of pCR (5, 6); however, most efforts with traditional biomarkers measured prior to chemotherapy lack accuracy, and most efforts focusing on monitoring changes in morphological characteristics are indicative only of a late-stage response (7–10).