Figure 6. HBV integration preference in male versus female HCC samples.

(a) Distribution of the enriched HBV integration regions in tumour samples. The red bars indicate the enriched regions found only in female samples, green bars represent enriched regions only found in male samples, and blue bars mean enriched regions found in both. In every 1M window of chromosomal region, the observed number of integration sites was tested against the expected number where all integrations distributed randomly across the genome. Enrichment was defined as P value smaller than 0.05 calculated by χ² test, which was performed separately in male and female samples. (b) Comparison of the numbers of breakpoints in tumour tissues of male and female samples. The HBV breakpoints number of male (left) and female (right) are shown. The box plots show the median (horizontal bar), 25th and 75th percentiles, and the whiskers of the plots show the smallest and largest values. P values was calculated by unpaired Student's t test. (c) Comparison of integration ratio of male and female HCC samples. The HBV integration ratio of male (left) and female (right) HCC samples are shown. P values were calculated by χ² test.