In addition, the involvement of MAPK members in MMP-2 and MMP-9 expression control is likely to be also indirectly regulated by DNA damage events, because DNA polymerase iota, which acts in translesion DNA repair, is able to increase the expression of both MMPs by inducing the activation of the JNK/activator protein 1 (AP-1) axis in ESCC cells [77]. Here, MMP9 is linked to esophageal squamous cell carcinoma.