PROS1 and laryngotracheoesophageal cleft: One possible reason for these results was that there were a lot of HCV-related LC or HBV-related LC patients with favorable treatment response for antiviral therapies during the follow-up period, which may be linked to the high survival rate in group A. On the other hand, the mechanism for the serum zinc level decline in HCV-related LC is presumed to involve the non-structural proteins (NS)3 and NS5A of HCV [41,42].