The human genome comprises four genes with homology to Scm, but only two that contain conserved MBT, SPM, and DUF3588 domains, SCMH1 and SCML2. SCMH1 functions in spermatogenesis (Takada et al., 2007), whereas little is known about SCML2, except that it is ubiquitously expressed and that deletions of its coding sequence are found in a subset of medulloblastomas (Northcott et al., 2009), suggesting it may have tumor-suppressive activity. The gene discussed is SCMH1; the disease is medulloblastoma.