Final answer:
In a BLASTX search, if the first match is to a "Hypothetical protein," it is recommended to investigate the protein's functions further.
Step-by-step explanation:
In a BLASTX search, if your first match is to a "Hypothetical protein," you should investigate the protein's functions further. This is because a "Hypothetical protein" is a term used to describe a protein whose function has not yet been experimentally determined.