Before joining Hopkins in 2009, he worked for 17 years in the pharmaceutical industry in both large pharmaceutical and small biotechnology companies. He carried out work in drug discovery research on enzymes involved in cardiovascular and neurological disorders. His early training in biochemistry focused on enzymology. Later in the pharmaceutical industry, Dr. Rojas was project leader for preclinical drug discovery projects through target proposal, assay development, high throughput screening, lead nomination and lead optimization.