MMP9 and melanoma: Intragenic methylation could suppress repetitive element transcription, and the methylated intragenic regions were related to higher levels of gene transcription [64].For example, in melanoma samples with high MMP-9 transcript levels, the DNA of the intragenic CpG-2 region of the MMP9 gene was highly methylated, and high mRNA and protein levels of MMP-9 in this region were verified in vitro [65].