None of the normal uterine biopsy specimens showed evidence of SAS1B transcripts (Figure 2A: U1–U7; Figure 1B: UTE) However, 30/38 (78.9%) uterine tumors tested positive for ASTL RNA (Figure 2, panels A–D) including specimens of grade 1 and grade 3 endometrioid cancers, serous papillary carcinoma, and MMMT. The gene discussed is ASTL; the disease is carcinosarcoma.