Compared with normal tissues, the PCMT1 gene is significantly more highly expressed in breast cancer, but its protein level is lower than that in normal tissues, revealing the influence of posttranslational modifications in breast cancer on PCMT1. In addition, the expression of PCMT1 is significantly related to the tumor stage of breast cancer, suggesting that it may be a prognostic marker of breast cancer. Here, PCMT1 is linked to breast cancer.