EML4 and neoplasm: In 2014, Blasco et al. designed sgRNAs targeting intron 14 of the EML4 gene and intron 19 of the ALK gene in mice, generated DSBs using Cas9, and generated EML4-ALK rearrangements in non-small cell lung cancer cells, which were able to promote tumor formation in the lungs of mice, demonstrating the importance of the CRISPR/Cas9 system for studying chromosomal rearrangements (Blasco et al., 2014).