Fold: Cystine-knot cytokines

disulphide-rich fold; common core is all-beta

Lineage:

1. Root: scop
2. Class: Small proteins
   Usually dominated by metal ligand, heme, and/or disulfide bridges
3. Fold: Cystine-knot cytokines
   disulphide-rich fold; common core is all-beta

Superfamilies:

1. Cystine-knot cytokines (5)
   1. Platelet-derived growth factor-like (2)
   2. Transforming growth factor (TGF)-beta (6)
   3. Neurotrophin (4)
   4. Gonadotropin, A and B chains (1)
   5. Coagulogen (1)