“…and the methods used for data analysis (e.g., peak calling). Third, ChIP-seq data contain numerous technical biases (Kidder et al, 2011), including formaldehyde crosslinking bias (Solomon and Varshavsky, 1985; Lu et al, 2010; Gavrilov et al, 2015), antibody specificity and variability problems (Parseghian, 2013; Schonbrunn, 2014; Wardle and Tan, 2015) (Figure S15), technical artifacts due to highly expressed regions of the genome (which are not corrected by regular input controls) (Teytelman et al, 2013; Park et al, 2013; Jain et al, 2015), bias due to genome fragmentation and PCR amplification (Bardet et al, 2011; Poptsova et al, 2014), etc. These biases can lead to false-positive and false-negative peaks, and they also significantly affect any quantitative estimates of in vivo TF binding levels derived from ChIP-seq data, in ways that we do not understand well enough to correct (Gavrilov et al, 2015).…”