Ectopic expression is when a gene is expressed in a cell or tissue where it is not normally present. Synonyms for this term include aberrant expression, anomalous expression, and non-canonical expression. Another similar term is ectopic activation, which refers specifically to the activation of a gene that is normally inactive or silenced. Other synonyms for ectopic expression may depend on the specific context of the gene or molecular pathway involved, such as inappropriate expression, ectopic induction, or ectopic production. Understanding the mechanisms and consequences of ectopic expression is important for studying genetic diseases, developmental disorders, and cancer.