Systematic errors in HiSeq data. A screenshot from the IGV browser  showing two systematic errors in the HiSeq dataset analyzed. These locations are not statistically significant under a chi-squared test for directionality bias (after correcting for multiple hypotheses), demonstrating the weakness of this test.
Meacham et al. BMC Bioinformatics 2011 12:451 doi:10.1186/1471-2105-12-451