Estimates of parameter κ from (eq 7) for several surrogate endpoints that result after fitting data with fixed values for the target number (m).

TE is the linear also called targeted effects model of (eq 5) and NTE2 is the non-targeted effects model of (eq 7). The average overall model uses the TE results for simple exchanges in 82–6 fibroblast cells. *Standard deviations (SD) for the values fit to the transformation experiment were not reported by Waligorski et al. [43] and we assumed a SD of 35% of the central estimate based on the maximum of results for other endpoints considered.