To determine if PTPRO plays any role in breast cancer, we first conducted reverse transcription-quantitative PCR (RT-qPCR) to estimate the mRNA levels of PTPRO in 37 breast tumor tissues and found that compared with their adjacent normal tissues, the mRNA level of PTPRO is significantly lower in 67.6% of cancer tissues (Figures 1A,B). This evidence concerns the gene PTPRO and breast cancer.