ABCC11 is an ATP-binding cassette transporter responsible for the transport of a diverse range of lipophilic compounds. A single nucleotide polymorphism (SNP) encoding an amino acid change has recently been shown to determine whether cerumen (earwax) is wet or dry. We hypothesised that this ABCC11 SNP may be associated with breast cancer risk because an association has been reported between wet earwax and increased risk of breast cancer. We therefore analysed the frequency of the functional SNP in 1342 cases and 2256 controls from two breast cancer studies of Caucasian women but found no evidence for an association with breast cancer risk.