NFKB1 and cancer: In addition, to investigate how isothiocyanates affect the activity of the promoter regions of these transcription factors, cancer cells were transiently transfected with reporter constructs encoding the wild-type MMP-9 promoter (MMP-9-WT), or an MMP-9 promoter bearing mutations in AP-1-binding sites (MMP-9-mAP-1) or the NF-κB-binding site (MMP-9-mNF-κB).