Similarly, a melanoma-specific transcription factor is able to activate HML2 LTRs (Katoh et al., 2011) and the RB protein, a downstream mediator of BRAF–MEK–ERK signaling often altered in cancers, is a key regulator of DNA methylation that can influence HERV expression (Li et al., 2010). The gene discussed is MAP2K7; the disease is melanoma.