activities of the individual elements or variants are measured by sequencing the transcribed reporter mRNAs and counting their specific barcodes. This approach can be used to rapidly profile the regulatory activity of thousands of variants at GWAS loci (Tewhey et al., 2016; Ulirsch et al., 2016). Finally, advances in genome-editing technologies—most notably clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated 9 (Cas9) systems—have opened up new avenues to rigorously assess the functional impact of genetic variation (Musunuru, 2013).
