highly significantP < 0.001
Among the 15 agINs, 13 showed extension-biased activity, one showed flexion-biased activity, and one showed an unbiased activity pattern, indicating a highly significant bias toward extension ( P < 0.001, binomial test); the grand averages of these 15 agINs also exhibited extension-biased activity ( P = 0.002, two-way ANOVA, Fig. 1 H ).