PHAX and hypotrichosis 1: In addition, RNA-IP experiments using anti-PHAX antibodies revealed an increased level of association of PHAX with pre-U2 in the cytoplasm in HHS patients’ cells (Figure 4f), thus lending support to the idea that, upon export, there is a failure to transfer the pre-U2 RNA from the CBC–PHAX–RNP to GEMIN5.