ceratin

1. There are many etiopathogenisis, but the main etiopathogenisis is the interaction of hormone, ceratin sebum and bacteria, which also decides the duration and severity of the disease.
   它的病因较多，但主要由激素、角蛋白、皮脂和细菌的相互作用而引起，这些因素决定病程的长短和严重程度。

noun

1. a fibrous scleroprotein that occurs in the outer layer of the skin and in horny tissues such as hair, feathers, nails, and hooves

   Synonym:    keratin