STAT2 and fibrosarcoma: In order to functionally characterize the cellular and molecular consequences of the p.(A219V) substitution, and in the absence of patient material, particularly dermal fibroblasts, we performed stable lentiviral transduction of STAT2-deficient U6A human fibrosarcoma cells [18, 19] with STAT2 WT and mutant (p.(A219V); p.(R148W)) constructs.