diff --git a/biomedical_schema/chemical_compound.mcf b/biomedical_schema/chemical_compound.mcf
index 9c9d2ab9..4c8d906a 100644
--- a/biomedical_schema/chemical_compound.mcf
+++ b/biomedical_schema/chemical_compound.mcf
@@ -18,6 +18,12 @@ typeOf: schema:Class
 subClassOf: dcs:Protein
 description: "An antibody is a kind of protective protein which is produced by the immune system when substances from the outer source invade the living organisms. The process of producing the antibodies is called immune response."
 
+Node: dcid:Association
+name: "Association"
+typeOf: schema:Class
+subClassOf: schema:Thing
+description: "An observed association between two entities."
+
 Node: dcid:BiomedicalEntity
 name: "BiomedicalEntity"
 typeOf: schema:Class
@@ -34,7 +40,7 @@ descriptionUrl: "https://www.ebi.ac.uk/chembl/"
 Node: dcid:ChemicalCompoundAssociation
 name: "ChemicalCompoundAssociation"
 typeOf: schema:Class
-subClassOf: dcs:ChemicalCompound
+subClassOf: dcs:Association,dcs:ChemicalCompound
 description: "Observed association between a chemical compound and another entity type."
 
 Node: dcid:ChemicalCompoundChemicalCompoundAssociation
diff --git a/biomedical_schema/disease.mcf b/biomedical_schema/disease.mcf
index 3dde0395..b601b2ed 100644
--- a/biomedical_schema/disease.mcf
+++ b/biomedical_schema/disease.mcf
@@ -8,7 +8,7 @@ descriptionUrl: "https://disease-ontology.org/"
 Node: dcid:DiseaseAssociation
 name: "DiseaseAssociation"
 typeOf: schema:Class
-subClassOf: dcs:Disease
+subClassOf: dcs:Association,dcs:Disease
 description: "The association between a disease and a second type of entity."
 
 Node: dcid:DiseaseDiseaseAssociation
@@ -20,13 +20,13 @@ description: "The association between two diseases."
 Node: dcid:DiseaseGeneAssociation
 name: "DiseaseGeneAssociation"
 typeOf: schema:Class
-subClassOf: dcs:DiseaseAssociation
+subClassOf: dcs:DiseaseAssociation,dcs:GeneticAssociation
 description: "The association of a disease with a gene."
 
 Node: dcid:DiseaseGeneticVariantAssociation
 name: "DiseaseGeneticVariantAssociation"
 typeOf: schema:Class
-subClassOf: dcs:DiseaseAssociation
+subClassOf: dcs:DiseaseAssociation,dcs:GeneticAssociation
 description: "The association between a disease and a genetic variant."
 
 Node: dcid:MeSHConcept
diff --git a/biomedical_schema/genome_annotation.mcf b/biomedical_schema/genome_annotation.mcf
index ebd3049b..00932eac 100644
--- a/biomedical_schema/genome_annotation.mcf
+++ b/biomedical_schema/genome_annotation.mcf
@@ -38,7 +38,7 @@ description: "The association between a gene and a genetic variant. This associa
 Node: dcid:GeneticAssociation
 name: "GeneticAssociation"
 typeOf: schema:Class
-subClassOf: dcs:GenomeAnnotation
+subClassOf: dcs:Association,dcs:GenomeAnnotation
 description: "Association between a genome annotation and another entity type."
 
 Node: dcid:GeneticVariant