HTRA1 and neoplasm: Most importantly, however, a significant proportion (34 %) of the downregulated genes in the module are apoptosis mediators, or have been reported to constitute putative tumor suppressors, notably FAS, SFRP2, GAS1, KLF2, LPL, SCARA5, PTGIS, SLIT3 and HTRA1 [37-49], including the metastasis suppressor RECK [50] (Figure 7).