PCSK9 and familial hypercholesterolemia: However, no differences in these biomarkers were observed between mAbs versus siRNA treatment, indicative of no additional benefits, with respect to non-LDL-C biomarkers, to be gained from the intracellular inhibition of PCSK9 translation in the patient segment investigated (patients with hypercholesterolemia driven by a high abundance of LDL particles) and within the considered range of LDL-C reduction.