KLRD1 and neoplasm: Cell surface receptors known to be bound with ex-HSP90 are (i) CD91/LRP1/A2MR expressed on tumor cells, immune cells, and EVs, (ii) toll-like receptors (TLRs), (iii) scavenger receptor expressed by endothelial cells-1 (SREC-1), and (iv) CD94/KLRD1 expressed on killer cells.