Authors’ contributions
S.S., K.K. and J.K. designed the study. J.K. and E.P.F. collected stem cell collection data. J.K. created the figures and wrote the initial version of the manuscript. S.S., E.K.M., N.W., C.M.-T., H.G. and K.K. reviewed and revised the manuscript. All authors have read and agreed to the published version of the manuscript. Aside from the funding for the clinical trials (GMMG-HD6 and GMMG-HD7) no separate funding was acquired.