library_construction_protocol: Genomic DNA was then extracted using a QIAamp DNA Blood Mini Kit (Qiagen) from all surviving iCMs of both groups. The gRNA-inserted regions were amplified by PCR prepare CRISPRi/a screen NGS sequencing libraries, which were sequenced on an Illumina HiSeq-4000 and analyzed as previously described (PMID: 27661255)