NFKB1 and Bloom syndrome: The expressions of both miRNAs were significantly reduced in BLM-treated IKBM mice (1.11 ± 0.05 and 1.04 ± 0.07) compared to WT + BLM treated mice (P < 0.05), indicating the regulation of miR-503-5p by NF-κB (Fig. 5 B, C).