MYC (C-MYC) is a regulator gene that codes for a transcription factor is believed to regulate expression of 15% of all genes. C-MYC is one of the genes that has been used to generate iPS cells in culture.
Human elongation factor-1 alpha (EF-1 alpha) is a constitutive promoter of human origin that can be used to drive ectopic gene expression in various in vitro and in vivo contexts. EF-1 alpha (or EF1a) is often useful in conditions where other promoters (such as CMV) have diminished activity or have been silenced (as in embryonic stem cells).