Immediately, we noted that ASS1 expression was commonly lost in such tumors, including hepatocellular carcinoma, renal cell carcinoma and platinum refractory ovarian cancer.8 Given the chemorefractory nature of sarcoma, we decided to perform an extensive immunohistochemical analyses for ASS1 in 701 primary tumors across 45 of the most common subtypes (Figure 1a; for the full scoring of the IHC, see Supplementary Table 1). The gene discussed is ASS1; the disease is renal cell carcinoma.