I'm sparing all the details. Maybe it's correct?
CCR5+ CD8+ T Cells Are Associated with Poor Response to PD-1 Blockade Therapy
https://www.mdpi.com/1422-0067/27/11/4963
"The Blockade:
Leronlimab cuts off the influx of CCL3 and CCL4 into the cell's receptors.
The Shredder Stalls: This shutdown immediately deactivates the internal GSK3$\beta$ enzyme. The molecular shredder stops running.
The Glycoprotein Stabilizes:
Without the shredder to destroy it, newly synthesized immature PD-L1 (~33 kDa) is allowed to mature, undergo N-linked glycosylation, and stabilize into the mature 45–55 kDa cell-surface glycoprotein.
The Upregulation:
The cornered tumor cell or circulating tumor cell (CTC) pushes these stabilized PD-L1 flags to its outer surface in a desperate, final attempt to build a new cloaking shield and survive the host immune assault".