When editing with three separate gRNAs (targeting AAVS1, HBB, and ZFPM2), ultra-deep sequencing of >500 tumor suppressors and oncogenes found no detectable variants (>0.002 VAF) that could be attributed to Cas9 activity or ex vivo expansion (aside from the expected EZH2 off-target site in the ZFPM2 treatment group). Here, HBB is linked to neoplasm.