Gilead Sciences has expanded its collaboration with the start-up Tango Therapeutics. Tango uses CRISPR gene editing to discover weaknesses in cancer cells and thereby identify new drug targets. Gilead began working with Tango in 2018. The firms are now expanding their partnership from 5 targets to 15. Gilead will pay Tango $125 million up front, make a $20 million equity investment, and pay up to $410 million for each of the potential 15 programs. Tango is also getting $30 million from private investors.