design: U937 cell line expressing Cas9, lentivirally transduced with gRNA targeting 20_45793962_45793982_+_1st_rep (target sequence: CCTGCAGCCCAGCATCAACGAGG), differentiated into macrophages using PMA followed by M2 polarization with IL10, IL4, and TGFb. Genomic DNA was extracted and CRISPRCas9 cut sites were amplified by PCR with Illumina-compatible adapters for amplicon sequencing on an Illumina MiSeq using paired-end 150 bp reads.