of protein-coding and ncRNA genes [119] associated with an unusual genetic phenomena termed “polar overdominance” [120], which may also occur in humans [121]. While these mutations are reasonably assumed to be regulatory in nature, their mechanistic basis has not been determined, although in the latter case, there is some evidence for the involvement of trans-acting miRNAs [119],[122]. In addition, linkage studies in a large family have recently identified the ncRNA AK023948 as a candidate susceptibility gene for papillary thyroid carcinoma [123].
