CD274 and cancer: In concordance with the results of the unbiased analysis presented above, we do not observe a significant correlation between cancer or AID incidence rate sex bias and the expression of key immune checkpoint genes (CTLA-4, PD-1, or PD-L1, Figure S3), or the extent of X-chromosome inactivation (quantified by the expression of XIST lncRNA [28], Figure S4).