The expression levels of p-AKT, CD9, CD63 and PD-L1 in KO + lymphoma cell + IXA4 group were significantly higher than those in KO + lymphoma cell group but similar to those in WT + lymphoma cell group and WT + lymphoma cell + IXA4 group, proving that IRE1/XBP1s is an important pathway downstream of Notch-1 (Figure 5). Here, CD9 is linked to lymphoma.