In addition, genes that are well known to be deregulated in cancer such as MYC, MKI67, ACPP, CTNNB1, KLK2, KLK4, PCNA, PMEPA1, NKX3-14,33,64–68 were also significantly deregulated (and in the same direction) in US-FNA samples, confirming the similarity of US-FNA samples and their prostate tissue counterparts. Here, KLK4 is linked to cancer.