How to match identifier to identifier in order to make a relationship in neo4j?

Question

[prithvi.mastermind]

I have used CREATE variable to assign already existing variable a numerical identifier using the following command:

MATCH (n:Subtype{name:"IM"})
SET n:Identifier
RETURN n

After that I wish to MERGE pathway node using specific identifier to my IM node but after running the command I get no relation

MATCH(n:Subtype{identifier:'IM'}), (p:Pathway{identifier:'R-HSA-69206'}) 
MERGE(n)-[:AFFECTS]->(p)

Please help to resolve