To this end, flow cytometric analysis showed that HSPCs (or LSK cells; lineage (Lin)−Sca1+cKit+) express PD-L1 at steady state and its expression was not altered after B16.F10 melanoma cell inoculation (Figure 2A), whereas it was significantly increased upon inoculation with immunogenic MB49 bladder cancer cells (Figure 2B). Here, KIT is linked to melanoma.