Using zebrafish “Avatars”, an animal model developed by the Cancer Development and Innate Immune Evasion lab at the Champalimaud Foundation (CF), led by Rita Fior, Mayra Martínez-López – a former PhD student at the lab now working at the Universidad de las Américas in Quito, Ecuador – and colleagues studied the initial steps of the Bacillus Calmette-Guérin (BCG) vaccine’s action on bladder cancer cells.