The discovery of a new immune suppressor, Siglec-15, and the lncRNA LINC00973, which activates Siglec-15 according to the ceRNA model, has been reported, which is very important for the immunotherapy of kidney cancer, especially in those patients in whom the role of PD-1/PD-L1 checkpoints has not been identified. Here, PDCD1 is linked to kidney cancer.