In Mongolian gerbils, there were two cases of abdominal scent gland epithelioma (both two-year-old males) and one case of histiocytic sarcoma located in the nasal area (age unknown, female; tumour cells expressed Iba-1 and vimentin, clone V9, and were negative for desmin and α-SMA-). This evidence concerns the gene ACTA1 and histiocytic sarcoma.