Professor O’Sullivan’s group identified and characterised in 2012 the then only known genetic mutation recurrently seen in Clear Cell Sarcoma of Kidney (CCSK), and have been working on the biologic implications of that mutation (YWHAE-NUTM2 fusion) since then, with very exciting results. Recently, one further mutation was identified in CCSK – this is within the BCOR gene which has a role in epigenetic regulation of gene transcription. Professor O’Sullivan’s group have now studied a very large cohort of cases of CCSK collected from international sources to total 159 tumours for these two genetic mutations. Their findings show distinct subsets of CCSK with the BCOR and YWHAE alterations. They have adopted several technical approaches specifically to investigate the epigenetic effect of BCOR ITD in cells. Their studies on YWHAE-NUTM2 are already advanced and they will be uniquely positioned to draw comparisons between the molecular mechanisms in their contributions to CCSK oncogenesis.