For dividing the metastatic patients into two groups, i.e., with high and low lncRNA expression, several methods were adopted in the included articles: (i) high expression and low expression, according to a HOTAIR/ACTB ratio of 1.368 in tumor tissues, obtained by the ROC method; (ii) high expression group: expression ratio ≥ median ratio; and low expression group: expression ratio≤median ratio; and (iii) high expression levels in their tumor tissues were equal to or more than 2‐fold that of corresponding normal tissues. This evidence concerns the gene ACTB and neoplasm.