Among a host of alternative promoters derived from mammalian TEs and driving protein-coding and non-coding gene expression [9,31-33], we consider three reports as landmark examples of TE insertions having a clear functional impact upon biology: an epigenetically regulated LTR upstream of the Agouti gene in rodents [34], an LTR alternative promoter for the colony stimulating factor 1 receptor (CSF1R) proto-oncogene in lymphoma [35], and the convergent evolution of multiple LTRs to act as promoters for the neuronal apoptosis inhibitory protein (NAIP) gene [36]. The gene discussed is CSF1R; the disease is lymphoma.