cEGF, or complement Clr-like EGF, domains have six conserved cysteine residues disulfide-bonded into the characteristic pattern 'ababcc'. They are found in blood coagulation proteins such as fibrillin, Clr and Cls, thrombomodulin, and the LDL receptor. The core fold of the EGF domain consists of two small beta-hairpins packed against each other. Two major structural variants have been identified based on the structural context of the C-terminal cysteine residue of disulfide 'c' in the C-terminal hairpin: hEGFs and cEGFs. In cEGFs the C-terminal thiol resides on the C-terminal beta-sheet, resulting in long loop-lengths between the cysteine residues of disulfide 'c', typically C[10+]XC. These longer loop-lengths may have arisen by selective cysteine loss from a four-disulfide EGF template such as laminin or integrin. Tandem cEGF domains have five linking residues between terminal cysteines of adjacent domains. cEGF domains may or may not bind calcium in the linker region. cEGF domains with the consensus motif CXN4X[F,Y]XCXC are hydroxylated exclusively on the asparagine residue.