LOH contributes to cancer by eliminating the normal, functional allele of a gene that suppresses tumor formation. Common mechanisms of LOH include chromosomal deletions, mitotic recombination, and gene conversion. The loss of tumor suppressor genes such as TP53, RB1, and BRCA1 can lead to the deregulation of the cell cycle, reduced apoptosis, and increased genetic instability, all of which contribute to the progression of cancer.
