Repeat unit G/C repeats 20 times in the reference sequence.
...CCCTGGGCTGGGGCGCCGGGGCGAGCGCGGCGGCGCGGAACCATGACAGAAGATGACCGAGGCGGCGCTGGTGGAGGGCCAGGTCAAGCTGCGGGACGGC
AAGAAGGTCGGGGCGCGTCGGGGGCGCGGGGGGGGGGGGCGCGGGCGCGGGCGGCGGCTCACGCTCCCCCCTGTCCCCGCAGTGGAAGAGTAGGTGGCTG
GTGCTGCGGAAGCCGTCGCCCGTGGCAGGTGAGCGGGGCGGGCGGGGGACGGGGGGCGC...