Enrichment of interactions between essential proteins in raw and high-confidence yeast PPI data sets.

All PaAverage number of interactions observed between essential proteins for 1000 simulations in which essential proteins were selected randomly from all proteins occurring in a network. In each simulation, the total number of selected proteins and their degree distribution were constrained to be identical to those of the actual essential proteins.bStandard deviation for simulations described above.针对1000次模拟实验，统计从某蛋白质相互作用网络的全部蛋白质中随机选取必需蛋白质（essential proteins）时，观测到的必需蛋白质间成对相互作用的平均数量。每次模拟实验中，被选取的蛋白质总数及其度分布（degree distribution）均被约束为与真实必需蛋白质的对应参数完全一致。b. 上述模拟实验对应的标准差（standard deviation）。