Table 1.

The number of samples n needed to get an overlap f ≥ f_c = 1 − ε, with confidence 1 − δ, for two PGLs of size αN_g

fc = 1 − ε	δ	n (10)	n (11)
0.02	0.5	87	104
0.05	0.5	170	218
0.10	0.5	290	383
0.20	0.5	553	743
0.50	0.5	2,300	3,142
0.02	0.1	178	195
0.05	0.1	270	319
0.10	0.1	412	507
0.20	0.1	736	930
0.50	0.1	3,026	3,883

We use α = 0.0046 (corresponding to a PGL of 70 genes) and α = 0.0068 (corresponding to a PGL of 76 genes) for refs. 10 and 11, respectively. For δ = 0.5, f_c = f*_n, and hence n represents the number of samples needed for an average overlap of 1 − ε. The effective number of genes used here (after preprocessing) was N_g = 15,125 for ref. 10 and N_g = 11,130 for ref. 11.