KLK3 and posterior cortical atrophy: In 2014, Yoneyama et al. developed a magnetic microbead-based immunoassay measuring the amount of α2,3-sialic acid-linked PSA in serum in a training set of 100 samples (non-PCA = 50 and PCa = 50) and then in a validation set of 314 samples (Non-PCa = 176 and PCa = 138) [68].