PLK4 and Lynch syndrome: Lynch syndrome tumors showed up-regulation of 1129 genes, e.g. genes involved in G1/S transition (CCNE, CCNH, E2F2 and CDK2), DNA replication (CDC45, RPA1, RFC5, MCM4 and POLD3) and chromosomal organization and mitosis (CCNB2, MLF1IP, CASC5, KIF2C and PLK4), which is in line with previous findings (Table 2) [16], [18], [35], [36].