Interestingly, we also transplanted C1498FF–mPD-1H or C1498FF-mock cells in PD-1H KO B6 mice and found that, similar to the observation in WT B6 mice, the C1498FF–PD-1H tumor growth was still faster than that of C1498FF-mock cells (mean radiance of C1498FF-mock versus C1498FF–PD-1H on day 21: 1.4 × 105 versus 4.3 × 107, n = 7, P = 0.01) (Supplemental Figure 6A). Here, VSIR is linked to neoplasm.