Research topic [Neo4j, recommendation system]

I'm a graduate student and want to write a master's thesis on using Neo4j to create a recommendation system, but I can't decide on a specific topic.
What topics do you think will be relevant to my research? I would be extremely grateful if you could help me make a choice!

I'm always thinking about healthcare so I would like to recommend looking into existing healthcare recommendation specs. One that has a lot of traction right now is the CQF Recommender as apart of FHIR. It's a part of a larger spec about clinical guidelines and not much work has been done with it academically and I'm not sure anyone is using Neo4j for implementation yet either.

I just found a theoretic paper on neo4j and recommendation yesterday, it is published at RecSys2020.

Here's an article about building patient journeys in neo4J.

You can start from here and build a recommendation system for patient advocates, or drug side effects etc.

There is a link to source code to ingest the Synthea patient data also in the article.