In our current study using the full-length HBc, to our surprise, we found that mutation E117A is always highly deleterious to viral RNA encapsidation and DNA synthesis in various arginine-deficiency contexts, including ARD-III, ARD-IV, and ARD-I + II + III + IV, but not in WT context (Fig. 3 and Supplementary Figure S3). Here, KRT88P is linked to hyperinsulinemic hypoglycemia, familial, 4.