ASS1 and sarcoma: In collaboration with a sarcoma pathologist, we applied an intensity score (from 0 to 3) for ASS1 expression similar to that used for other biomarkers, such as the estrogen and androgen receptor, and also similar to that used for ASS1 in other tumors where heterogeneous expression is noted with 0 being no staining, +1 being 1–25% staining, +2 being 26–50% staining and +3 being 50% or greater staining.