IL15 and neoplasm: Considering the different target cells of IR780 and IL-15, the MMP2-sensitive linker DSPE-PEG2000-MMP2 sensitive peptide-Maleimide (DSPE-PEG2000-MMP2 sensitive pep-Mal) was used as linker to modify IL-15 on the surface of NIL-IM-Lip, which could achieve the xenotype cell delivery and release IL-15 in the tumour microenvironment with enzyme MMP2 to strengthen the coactivation of CTLs and NK cells.