As shown in Fig 1C measurement of separase activities and comparison of calculated SAD values between healthy controls (n = 7) and patients with MDS (n = 37), sAML (n = 8) and de novo AML (n = 9) revealed higher SAD values in sAML (mean 13.9 ± 0.99, range 9.3 to 17.9) samples when compared to the control group (mean 11.6 ± 0.29, range 10.7 to 13.0, p = 0.0463), the MDS group (mean 10.0 ± 0.49, range 5.1 to 16.7, p = 0.0011), and the de novo AML group (mean 8.2 ± 0.76, range 4.2 to 11.4, p = 0.0003) indicating an association between high SAD values and disease progression in MDS patients. The gene discussed is ESPL1; the disease is myelodysplastic syndrome.