Wan, Y.-W. et al. PLoS One 9, e87782 (2014).

MicroRNAs (miRNAs) regulate diverse processes in the cell by tuning the levels of target RNAs. By comparing miRNA expression between tumor and matched nontumor tissue, scientists can identify miRNAs that play a role in cancer. Two common profiling methods are miRNA microarrays and high-throughput miRNA sequencing. A report by Wan et al. indicates that results from these platforms should be interpreted with caution. The researchers find very low concordance between array and sequencing data on identical ovarian cancer samples from The Cancer Genome Atlas. Moreover, miRNAs associated with survival in ovarian cancer do not overlap between the two platforms. The causes of the discordance have yet to be identified.