FAS and breast cancer: To evaluate the role of TRAIL-R2, FAS and ICAM-1 in increasing NK cell-mediated apoptosis of cytokine-treated BC cell lines, we performed neutralization assay by pre-incubating NK cells with antibodies that recognize TRAIL, FAS-L and anti-LFA-1 which are ligands for TRAIL-R2, FAS and ICAM-1 respectively (Fig. 2C, D) [23–25].