| Source Element | Usage | Target |
| SubstanceProtein | UseExtension | http://hl7.org/fhir/5.0/StructureDefinition/extension-SubstanceProtein |
| SubstanceProtein.id | UseExtensionFromAncestor | - |
| SubstanceProtein.meta | UseExtensionFromAncestor | - |
| SubstanceProtein.implicitRules | UseExtensionFromAncestor | - |
| SubstanceProtein.language | UseExtensionFromAncestor | - |
| SubstanceProtein.text | UseExtensionFromAncestor | - |
| SubstanceProtein.contained | UseExtensionFromAncestor | - |
| SubstanceProtein.extension | UseExtensionFromAncestor | - |
| SubstanceProtein.modifierExtension | UseExtensionFromAncestor | - |
| SubstanceProtein.sequenceType | UseExtensionFromAncestor | - |
| SubstanceProtein.numberOfSubunits | UseExtensionFromAncestor | - |
| SubstanceProtein.disulfideLinkage | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.id | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.extension | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.modifierExtension | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.subunit | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.sequence | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.length | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.sequenceAttachment | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.nTerminalModificationId | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.nTerminalModification | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.cTerminalModificationId | UseExtensionFromAncestor | - |
| SubstanceProtein.subunit.cTerminalModification | UseExtensionFromAncestor | - |