When CSF from communicating hydrocephalus patients was compared to CSF from control subjects, four proteins, vimentin (VIM), protocadherin alpha subfamily C2 (PCDHAC2), glutathione synthetase (GSS), and prolyl 4-hydroxylase subunit beta (P4HB), were found in significantly higher abundance in control subjects (Fig. 1a and Table 2). This evidence concerns the gene PCDHAC2 and communicating hydrocephalus.