Those examined in this study (Z, S, D, H) have been shown to be expressed by microglia and indeed cathepsins H, S, and Z show some selectivity for myeloid lineage cells (Akahoshi et al., 2007; Kominami et al., 1985; Wendt et al., 2008) though the former two are also elevated in astrocytomas (Flannery et al., 2003; Kominami et al., 1985). The gene discussed is CTSH; the disease is astrocytoma (excluding glioblastoma).