CDKN1A and HELLP syndrome: Moreover, in early-onset PE complicated by the HELLP syndrome, the H-score of overall p21 was reduced, whereas phosphorylated-p21 was significantly elevated in fCTBs, possibly a compensatory mechanism in a crisis situation induced by the HELLP syndrome, by which the stress protein p21 is trying to be stabilized and possibly translocated to the cytoplasm, where it could exert its anti-apoptotic function but hardly affect the transcription of fusion-related genes.