TLR4 and granular corneal dystrophy type II: In the context of ACD, the treatment of keratinocytes with phenylenediamine (PPD) and 2,4-dinitrochlorobenzene (DNCB), increased the synthesis of HA through the induction of Hyaluronan Synthases (HS) 1 and 2, resulting in the formation of proinflammatory LMWHA fragments that interacted with TLR4 and activated the NF-κB signaling axis [55,56].