The two-tailed p-value indicates the statistical significance associated with testing whether the slope of the dose-response curve is different from zero. All values are given to one significant figure. When there is no dose-related effect or the slope is negative, then “P=1.” appears. The lowest p-value reported is p<0.0005.
Lower and upper 99% confidence limits are shown for each TD50. When the abbreviation “n.s.s.” appears for either the lower or upper confidence limit, it denotes not statistically significant. Whenever the statistical significance of TD50 is p>0.01, then the upper 99% confidence limit will not be calculated. When the lower confidence limit is “n.s.s.” this usually indicates that there were no tumors or only one tumor of the specified type in the experiment, and the lower confidence limit was not estimable. Occasionally the n.s.s. occurs for the lower confidence limit because 100% of dosed animals had the tumor(s) of interest and hence no lower confidence limit could be estimated with summary data.