 In 2005, Andrews shelved Sierra Sciences' efforts to identify the telomerase repressor protein, instead switching to the "brute force" strategy of developing assays to screen large numbers of semi-random chemicals to determine whether they induced telomerase.In November 2007, after nearly two years of screening, Sierra Sciences discovered the chemical C0056784, which induces approximately 6% as much telomerase as is found in the immortal cancer cell line HeLa.In 2008, using C0057684 as a positive control, Sierra Sciences developed a much more sensitive real-time PCR based high-throughput screening assay, the "hTERT RT-PCR assay," with which they were able to screen 4,000 chemicals per week.