Sgs1 is a non-replicative RecQ-like DNA helicase in yeast (Sun et al. 1999) and a homolog of the human Bloom syndrome (BLM) helicase, the inactivation of which causes a rare genetic disorder called Bloom syndrome (BS), which is characterized by aberrant recombination, chromosome instability, increased predisposition to cancer, short stature, and immunodeficiency (Ellis et al. 1995; Mirzaei and Schmidt 2012; Cunniff et al. 2017). The gene discussed is BLM; the disease is Bloom syndrome.