Indeed, while individual germline knockout (KO) of either Mafg or Mafk do not lead to discernable defects in the lens, their compound deletion in mice, specifically as Mafg−/−:Mafk+/-, results in cataracts from age 4-months onward (Agrawal et al., 2015). The gene discussed is MAFK; the disease is cataract.