We further found that a published derivative of MCF10A cells, MCF-MekDD, which we generated by infection of MCF10A cells with a retrovirus encoding an activated mutant of Mek (an Erk activator), displays significantly lower Irf6 levels than the parental MCF10A cells in 3D culture (Fig. 5b) [39]. This evidence concerns the gene MAP2K7 and infection.