There was a moment before a recent high-stakes argument at the U.S. Court of Appeals for the Federal Circuit began when the lawyers for Gilead Sciences Inc. were huddled together and realized something.

The outside counsel—Fish & Richardson partners Juanita Brooks, Deanna Reichel and Betsy Flanagan—and the in-house Gilead lawyers—Lorie Ann Morgan, vice president, intellectual property, and Andrea Hutchison, associate general counsel IP litigation—were all women.