KLK3 and prostate neoplasm: The steep increase in incidence in most countries in recent decades[2] is generally attributed to the increased detection of indolent prostate neoplasms (i.e. use of prostate-specific antigen [PSA] tests as screening tools)[3] a potentially increased exposure to unknown risk factors[4] accompanied by a sustained decrease in mortality[5], which, in Spain started in the late 1990s[6].