KMT1D/EHMT1 that specifically mono- and dimethylates lysine 9 of histone H3 (H3K9me1 and H3K9me2, respectively), but also methylates lysine 27 of histone H3 was overexpressed in ESCC in comparison with normal epithelium and positively associated with high tumour grade, stage, depth of invasion and lymph node metastasis. Here, EHMT1 is linked to esophageal squamous cell carcinoma.