An oligonucleotide primer or probe comprises the nucleotide sequence of any of SEQ ID NO. 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 44 61 62 or 63. The oligonucleotide primer or probe is useful for the detection of the methylation status of a gene. The oligonucleotides find application in the diagnosis and treatment of cancer.