The authors have retracted this Correspondence. After the publication of this correspondence, it came to the authors’ attention that the control RAG2−/− mouse was a RAG2−/−γc−/− mouse. This point resulted in the conclusions being considered invalid. The authors apologize to the journal and its readers for any inconvenience caused. https://doi.org/10.1038/s41423-021-00716-6International audienceThe authors have retracted this Correspondence. After the publication of this correspondence, it came to the authors’ attention that the control RAG2−/− mouse was a RAG2−/−γc−/− mouse. This point resulted in the conclusions being considered invalid. The authors apologize to the journal and its readers for any inconvenience caused. https://doi.org/10.1038/s41423-021-00716-