RYR2 and hypothyroidism: As might be expected with the disorganization of T-tubules with thyroid deficiency, the nearest neighbor distances (NNDs) measured between RyR2 cluster centroids were significantly greater in the PTU condition compared with either control EU or T3-treated myocytes (714 ± 15 vs. 588 ± 14 or 630 ± 11 nm, respectively) (Fig. 5C).