Ribosome profiling is a sequencing technique that detects regions in mRNAs that are being translated. Using this technique, researchers have observed mysterious patterns of translation in many transcripts believed to be non-coding (lncRNAs, or long non-coding RNAs). The patterns are very similar to those observed in protein-coding genes but the translated proteins are generally smaller. Aside from their sequence, we know nothing about these peptides. Are they functional? Do they reflect some background noise of the translation machinery?