Under a previous CIRM Award, we developed a stem cell based “heart on a chip” model for predicting toxic responses to drugs. We have now applied this model towards understanding potential toxicities of drugs used for COVID19 treatment and over the past 12 months, have successfully demonstrated a correlation between what can be detected on our chip in the laboratory vs. real outcomes in the clinic. We will continue to build off this effort by screening for potential risks of novel combinations of frontline therapies for COVID19.