Don't go in circles: confounding factors in gene expression profiling.

Quantification of gene expression is a crucial research tool in the life sciences, which makes it important to identify any factors that could compromise its accuracy. One of these factors are non‐polyadenylated (poly(A)) transcripts, including circular RNAs (circRNAs) that can skew quantification of gene expression as they resemble messenger RNAs (mRNAs). Here, we highlight the impact circRNAs and other poly(A) transcripts have on gene expression profiling and the biological conclusions drawn from such experiments. We also propose easily adoptable strategies to increase the accuracy of gene expression quantification.