RLN2 and neoplasm: Of the tumour tissues tested, expression of the 10 kDa S100A4 protein was strongly detectable in MDA/EGFP tumour tissues but was decreased to almost undetectable levels in all MDA/RLN2 xenograft tissues (Figure 9b) indicating the down-regulation of S100A4 during long-term exposure to RLN2 to be also effective in vivo.