Corrupting, creating, and expropriating enhancers through mutation or chromosomal aberrations. By destroying cis-element integrity and impairing factor binding, mutations corrupt enhancer function. Corruption may involve a complete loss of activity (if the factor affected is essential), partial loss of activity (if the remaining enhancer components can confer some degree of transcriptional activation), or acquisition of ectopic activity distinct from that of the wild-type enhancer. Mutations may generate cis elements that permit transcription factor binding, following by binding of additional transcription factors and coregulators to generate an enhancer at a site normally lacking an enhancer. Chromosomal inversions or translocations can expropriate a gene’s enhancer, transferring it to another gene, thus creating an ectopic gene-regulatory mechanism. A, gene normally controlled by enhancer; B, gene that expropriates the enhancer.