In the current study, we found that KRT7-AS reduced levels of the oncogenic KRT7 protein in lung and breast cancers; to our surprise, KRT7-AS increased the amounts of phosphatase and tensin homolog deleted on chromosome ten (PTEN), a key tumor suppressor [38–41] and pro-apoptotic modulator in cancer cells [42, 43]. This evidence concerns the gene PTEN and breast cancer.