Thanks Ken, for asking about this important topic.
I read recently that the growth in Boston has pushed it into a clear #1 position, and that it has indeed hurt both the SoCal and NorCal regions.
One other region that has really just steamrolled along is North Carolina. For more than 30 years they have been incentivizing their biotech industry. This location is probably the single most supportive place there is to start a company -- there are so many resources available for you, so many service companies waiting to assist, etc.
“Humility is not my forte, and whenever I dwell for any length of time on my shortcomings, they gradually begin to seem mild, harmless, rather engaging little things; not at all like the glaring defects in other people’s characters.” - Margaret Halsey