In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

Decreased histamine H1 receptor binding in the brain of depressed patients.
histamine H1 receptor

Effects of the histamine H1 antagonist chlorcyclizine on rat fetal palate development.
histamine H1

Adipose tissue as a source of nicotinamide N-methyltransferase and homocysteine.

nicotinamide N-methyltransferase