PGR and esophageal cancer: Other software algorithms also provide data highly correlated with pathologist scores, e.g., human epidermal growth factor receptor 2 (HER2) [28-34], estrogen receptor [35-39] and progesterone receptor [37-39] in breast cancer, DNA mismatch repair proteins in esophageal cancer [40], and epidermal growth factor receptor signaling molecules in colon cancer [41], among other biomarkers.