He and I are related by blood.

There is a complex love triangle between them.

His claim does not match the actual relationship.

His success had a cause-and-effect relationship with his efforts.

This is the book that I am reading.

That issue is irrelevant to our discussion.

His opinion is irrelevant to this issue.

The police only informed the authorized persons about the information related to the incident.

There are many interests involved in this project.

It's difficult to understand the context of this sentence.