SRPX and pachyonychia congenita: Furthermore, the interplay between these four genes increases during tumor development, as evidenced by increased correlation between the expression levels of perlecan/HSPG2 and LAMB3 or perlecan/HSPG2 and SRPX in primary PC and metastatic PC compared to normal tissues in the MSKCC dataset (N = 179) (Taylor et al., 2010) (Figure 3C).