Surprisingly, both R1 and R2 cells upregulated FAS and TNFSF10. While the overwhelming majority of studies on FAS and TNFSF10 have explored their role as initiators of apoptosis, sporadic reports suggest that they could actually be drivers of cell proliferation, migration, and invasion, and therefore contributors of tumor progression [26]. This evidence concerns the gene TNFSF10 and neoplasm.