Indeed, we found that CD44 knockdown significantly increased formation of CIC structures between tumor and NK cells (Fig. 5a, b), and concomitantly reduced the survival of PLC/PRF/5 cells that were co-cultured with NK92MI cells (Fig. 5c and Supplementary Fig. S6a); conversely, overexpression of CD44 significantly reduced CIC formation (Fig. 5d, e) and rescued tumor cells from immune killing by NK92MI cells (Fig. 5f and Supplementary Fig. S6b). This evidence concerns the gene CD44 and neoplasm.