To explore whether the uptake of exogenous serine is mediated by the amino transporter, we depleted SLC38A1 by using shRNAs in CD34+ cells via lentiviral infection (Fig. 4e, f), leading to the increase of serine levels in the conditioned medium (CM) from cells with SLC38A1 knockdown (Fig. 4g). This evidence concerns the gene SLC38A1 and infection.