DNMT1 expression is enhanced in metastatic melanoma. (A) Comparison of DNMT1 mRNA expression in normal skin, nevus, and primary melanoma samples using GSE3189 microarray dataset. (B) Comparison of DNMT1 mRNA expression in primary melanoma, stage III, and stage IV metastatic melanoma tissues using the GSE8401 microarray dataset. (C,D) Representative IHC images and H-score quantification of DNMT1 in normal organ tissues, stage III, and stage IV metastatic melanoma tissues from the TMA cohort. Scale bars = 20 μm. (E) Distribution of DNMT1 mRNA levels in metastatic melanoma patients with hemizygous deletion, diploid, and gain using the TCGA metastatic melanoma dataset (n = 367). Data represent the mean ± SD. ns: not significant, * p < 0.05, ** p < 0.01, *** p < 0.001, and **** p < 0.0001.