It was a patient-reported outcome, one that could actually be seen in the mirror, that alerted researchers they might be on track in their phase I/II study of cystinosis. The patient noticed that for the first time in his life his hair had become darker, like his brother’s. It was all because the rare disease inhibiting the pigment in his body was being impacted by the treatment. “It’s a secondary issue, but I find it fascinating,” Avrobio Inc.’s CEO, Geoff MacKay, told BioWorld. “When you run trials like this, you stumble upon some fascinating results.”