We devote this short piece to highlight one recent article published in Cell Stem Cell, reporting the correction of large chromosomal inversions of the factor VIII (F8) gene in cells from Hemophilia A patients using the CRISPR-Cas9 technology, one of the first attempts to edit large segments of chromosomes in patient cells using such methodology. The corrected cells were found free of off-target mutations and producing functional factor VIII in hemophilia mouse model. This work heralds another major advance in bringing CRISPR closer to the therapeutic reality.