SIX1 and heart failure: Several have been shown to be adversely associated with heart failure, namely the transcription factors HOP homeobox (Hopx) (Trivedi et al 2011) and Six homeobox 1 (Six1) (Delgado-Olguin et al 2012; Wu et al 2014), the cytoskeletal regulator tropomodulin 4 (Tmod4) (Zhao et al 2013), and the metabolic gene nicotinamide riboside kinase 2 (Nmrk2) (Ruggieri et al 2015).