SMAD2 and Hermansky-Pudlak syndrome: To sum up, we are the first to demonstrate that HKL could prevent scarring by inhibiting the proliferation, migration and activation abilities of HSFs both in vitro and in vivo. In addition, this work further demonstrated that HKL alleviated HPS formation by inhibiting TGF-β/Smad2/3 signaling pathway through a dependent way.