NSMCE2 and cancer: This is apposite because Smc5/6 has an essential role in maintaining cellular genomic stability and knock-out of both Smc6 and NSMCE2 (a subunit of Smc5/6) are embryonic lethal in mice [14,15], Moreover, loss of Smc5/6 may predispose to genetic errors under conditions of DNA damage [16], and reduced expression of the NSMCE2 subunit is associated with increased cancer incidence in mice [15].