Consistently, differential gene expression analysis by RNA-sequencing revealed that CD56 mRNA is indeed highly and specifically expressed in NK-92-sensitive cells (hTERT-HME1 and BT549) but absent (SKBR3, BT20, MCF-7, MDA-MB-231, BT474, T47D and HCC1500) or very faintly expressed (HCC1954) in the NK-92-resistant breast cancer cells (Supplementary Fig. 1B). The gene discussed is NCAM1; the disease is breast cancer.