CLDN4 and cancer: After incubating cancer cells with D@LPs or D@C-LPs for 4 h, the fluorescence intensity of CLDN4-positive ASPC-1 and KPC960 cells was higher with D@C-LP treatment than with D@LP treatment, whereas the fluorescence intensity of CLDN4-negative A549 cells was similar with D@C-LP and D@-LP treatment.