Membrane-bound muscle cell IL-15 was able to induce CD8+NKG2Dhigh T cells in vitro and might therefore contribute to the generation of CD8+NKG2D+ positive T cells in the inflamed muscle of PM patients as indicated by highly prevalent CD8 and NKG2D double positive cells in PM biopsy specimens. The gene discussed is KLRK1; the disease is polymyositis.