TFPI2 and fibrosarcoma: On the other hand, as supported by findings obtained with a human fibrosarcoma cell line (HT-1080) and normal human fibroblasts, the RAS oncogene, which can be mutated in NSCLC (Zochbauer-Muller et al, 2002), may also contribute to a downregulation of TFPI-2 gene expression (Izumi et al, 2000).