To test the effects of Clu on HSC differentiation in vitro, cultured Cas9-expressing oHSCs and wild-type (WT) yHSCs were respectively infected with lentiviruses to knock out or overexpress Clu. Eight days after infection, cells were sorted and quantified based on the expression of myeloid markers (FcR+/Mac-1+) or megakaryocyte ratios (Extended Data Fig. 2a). The gene discussed is CLU; the disease is infection.