Short CAG repeat lengths also correlate with early onset of PCa suggesting that early tumorigenesis is dependent on a more active AR.[11][12] The biological significance of polyglycine (GGC/N) repeat in the exon 1 is less clear; hence, some studies have proposed that the size of the glycine repeats might increase the PCa risk.[35][36][37] Chang et al. suggested that AR alleles with ≤ 16 GGC repeats are associated with PCa risk. The gene discussed is AR; the disease is posterior cortical atrophy.