Moreover, there are 2 polymorphic trinucleotide repeats in exon 1 of the AR gene that encode poly-glutamine (CAG)n.[9] Androgens are of great significance in the occurrence and progression of PCa, whose function is realized via the androgen receptor.[4] Previous studies have observed that CAG repeat length differed in different populations, and it was inversely connected to the AR gene transcription activity, which could meditate the AR's reaction to androgens. The gene discussed is AR; the disease is posterior cortical atrophy.