Figure 3 shows a plot of estimates of Z1 versus Z0 for all pairs of Lung Cancer study subjects with a kinship coefficient estimate greater than 0.025. All study subjects were expected to be unrelated, but this is clearly not the case. Based on expected values (+/− 2 SD), we inferred 14 pairs of full sibs and 5 pairs of half sibs. In addition, there is one parent-offspring pair and 36 pairs of duplicates, including a pair of identical twins. Two of the duplicate pairs could not be documented as coming from the same subject and were removed from the data set.
