To ensure that invasive tumour formation did not reflect off-target effects by lentiCRISPR reagents, we designed additional sets of sgRNAs to target CDKN2A, SMAD4 and TP53 (CDKN2A#3, SMAD4#2 and TP53#3) to generate HPDEKECST2 and HPDEKCST2 (Supplementary Fig. 15B–E). This evidence concerns the gene SMAD4 and neoplasm.