Distance between Transcription Start Site (TSS) and CpG island. ATSS: all promoters; MUTSS: most upstream promoter (most 5' promoter); MTSS: middle promoter; MDTSS: most downstream promoter. Zero distance indicates the TSS is within the CpG island. The number in longer distance includes that in the short distance. MUTSS has 80% more chance to be in CpG island than MDTSS.