Kallikrein 12, also known as Kallikrein-like5 (KLK-L5), is a trypsin-like serine proteinase. It was discovered by cloning the kallikrein locus on chromosome 19, and was found to be similar to the other kallikrein family genes. It is produced by a number of tissues, including pancreas, salivary gland, breast, prostate, uterus, lung, thymus, thyroid, brain, stomach and colon. Kallikrein 12 message has been reported to be decreased in breast cancer. Different splice variants of kallikrein-12 have been identified; a 254 amino acid form, 248 amino acids form, and a truncated 111 amino acid form.