Loss of heterozygosity - origin or result of carcinogenesis

Loss of heterozygosity has recently been discussed in the field of carcinogenesis, since loss of tumor suppressor gene has been believed to play a key role in carcinogenesis. However, recent evidence suggests that the loss of heterozygosity is a non-specific process in tumor progression rather than a specific process of carcinogenesis. Most loss of heterozygosity demonstrated by RFLP does not show the loss of tumor suppressors in a strict sense. We have to change our concept that loss of heterozygosity exclusively induces malignant phenotypes in cells. A likely explanation is that loss of heterozygosity is a general and rather stochastic process in tumor progression, and is due to loss of DNA replication fidelity. Detection of loss of heterozygosity without functional analysis may only accumulate meaningless data in tumor biology.