NFKB1 and embryonal carcinoma: Conversely, the 1B isoform is responsive to NF-κB in P19 mouse embryonic carcinoma cells, mouse primary cortical neurons (Paradkar and Roth, 2006a, 2006b; Ingrassia et al., 2012) and to HIF-1 alpha in HepG2 cells (Wang et al., 2010; Qian et al., 2011).