PTGDR and cancer: In recent years, lncRNAs were found out relating with human cancers and more than thousands of lncRNAs have been found and reported, such as AFAP1-AS1,[80] H19,[81] UCA1,[82]and HOTAIR.[83] More and more reports point out that lncRNAs could act as tumor markers in both diagnosis and predicting the prognosis.[84] Currently, however, there are a few meta-analyses to summarize the study of lncRNAs and molecular markers in prognosis of cancer.