More confounding are the dynamic conditions that impact non-B DNA structure formation (e.g. negative supercoiling,
binding proteins, chromatin structure, epigenetics, DNA transactions), are not typically included in the search criteria. In support of this, we have found that cytosine methylation within CpG repeats can facilitate and stabilize Z-form DNA, impact nucleosome assembly, and induce higher mutation frequencies in human cells and mouse chromosomes (Wang et al, unpublished data). Thus, structure predictions based on computer programs can only serve as a preliminary screening/identification step.