GRIA2 and dermatofibrosarcoma protuberans: Vivero et al. demonstrated that GRIA2 was a useful marker for distinguishing SFT from most mimics, as 89 % of SFTs were GRIA2-positive, while only 5–10 % of other soft tissue tumors were positive, except for dermatofibrosarcoma and myoepithelioma [4].