PTGS2 and cancer: Most slides from cancer-free tissue lacked expression of CCND1, CD44, CDH1, EGFR, ERBB2, KIT, keratins, NOTCH1, PAK1, PTGS2, SNAI1, and VIM but showed staining of MUC1, HIF1A, NKX2-1, SFTPC, and STAT3, which were also found in AdCa.