Mutant Ferret Brain (IMAGE) Howard Hughes Medical Institute Caption In the mutant ferret, neural progenitor cells form abnormal clumps (in box) and differentiate earlier in the developing brain compared with the normal ferret. Credit M. Johnson et al./Nature 2018 Usage Restrictions Must use with credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.