The Status of the P Versus NP Problem
A great review in the latest Communications of the ACM on the P vs. NP problem. For an introduction to the topic, see the Wikipedia article here. This is very relavent to the detection of gene-gene interactions in genome-wide association studies.
Fortnow L. The Status of the P Versus NP Problem. Communications of the ACM Vol. 52 No. 9, Pages 78-86 (2009). [ACM]
Fortnow concludes with "The P versus NP problem has gone from an interesting problem related to logic to perhaps the most fundamental and important mathematical question of our time, whose importance only grows as computers become more powerful and widespread."