diff --git a/src/mol-model/structure/model/properties/sequence.ts b/src/mol-model/structure/model/properties/sequence.ts
index fa3512028b76ee1ff6d27fede1890132e7ef38b7..f10338b174124e571eb7f069bd0d34da39eb8001 100644
--- a/src/mol-model/structure/model/properties/sequence.ts
+++ b/src/mol-model/structure/model/properties/sequence.ts
@@ -15,6 +15,8 @@ interface Sequence {
 // TODO lift to model/sequence/ folder
 // TODO add one letter code sequence string
 // TODO add mapping support to other sequence spaces, e.g. uniprot
+// TODO add sequence kind, e.g. protein, dna, rna (alphabets?)
+// TODO sequence alignment (take NGL code as starting point)
 
 namespace Sequence {
     export interface Entity {