In conclusion, this research essentially identified promoter methylation of miR‐155‐5p regulated by EZH2 as an important factor contributing to the low expression levels of miR‐155‐5 p in PCa cells, thus promoting the PCa cell malignancy through alleviating the suppression of SMAD2 and TAB2 (Figure 7). This evidence concerns the gene SMAD2 and posterior cortical atrophy.