CpG dinucleotides in the context of the CpG island located in transcription start site. The thin black line corresponds to the sequence of DNA. Below this, a single black bar corresponds to the predicted CpG island location. Distances in base pairs to +1 site are included, as well as an arrow indicating the start site of exon s1. Primers for both regions analyzed, CG1 and CG2 are indicated with arrows.