One other individual I'd like to mention, who picked up the biochemistry, the purification that Tom had initiated, was a young student named Ted Usdin, who's now at the NIH. Ted labored almost completely on his own to perfect the purification scheme. He ended up purifying a protein we then called ARIA, for Acetylcholine Receptor Inducing Activity, which was subsequently renamed neuregulin. But on his own, he didn't have many collaborators, but he purified it by our estimates a million-fold and got to the point where could consider sequencing the protein. That was really the beginning of the modern era, for me, in molecular biology.

We sequenced the terminal 30 or so amino acids and knew the family of proteins that it belonged to. It was crushing when other groups, talented groups, sequenced the similar protein and gave it a different name. It's terrible when your daughter marries and someone changes her name, but when someone changes the name of your protein you've worked on for 20 years, it's devastating. The protein family became known as the neuregulins, as it is today.

At the same time, this was all focused on a protein that regulated the number of acetylcholine receptors in skeletal muscle. It's based on the theme that the incoming motor axon can stimulate the muscle cells to synthesize synapse-specific molecules, one of them being the acetylcholine receptor. We never said this was the only factor that had this capability and the more we learn about molecular science, the more we realize that there are many ways to bring about a complex phenomenon. When someone criticizes one's work by saying you can eliminate that molecule and still get the phenomenon, that to me is not a strong criticism. It means you just have to investigate further and find out the true complexity of the biology.