Screening for antibodies against the TIF1γ antigen is performed to investigate polymyositis, dermatomyositis, and overlay syndrome.
Antibodies against the TIF1γ protein (formerly known as p155 / 140 antibodies because antibodies were detected against the p155 portion of the molecule corresponding to the most clinically relevant autoantibodies) are associated with dermatomyositis. In dermatomyositis occurring in adults (but not in children), the presence of TIP1γ antibodies indicates a malignancy. In children, the presence of TIP1c antibodies is associated with cutaneous lesions (Gottron's pus, ulcers, edema).
The TIF1γ antigen corresponds to the Transcriptional Intermediary Factor-γ1.