In a first attempt to analyze NK-92 degranulation (CD107a surface expression) following coculture with breast cancer target cells, we used, in association with CD107a staining, CD56 (the archetypal phenotypic marker of NK cells) staining to discriminate between NK-92 (CD56-positive) and breast cancer cells (expected to be CD56-negative) (Supplementary Fig. 1A). Here, NCAM1 is linked to breast cancer.