However, Tiju et al. observed that, in aggressive forms of BCC compared to those with milder evolution, there is a higher number of macrophages, which can induce the secretion of MMP-9 in BCC cells and enhance tumor invasion through the activation of a p38 MAPK/NF-kB/COX-2 cascade [175]. Here, NFKB1 is linked to skin basal cell carcinoma.