The first time Dr. Emily Chen, a hepatologist in San Francisco, reviewed her patient’s lab results, she nearly dropped her coffee. The numbers didn’t lie: her 38-year-old client, a former Wall Street analyst turned tech entrepreneur, had ALT (alanine aminotransferase) levels at 120 U/L—three times the upper limit of normal. His AST (aspartate aminotransferase) wasn’t […]