PDCD1 and ovarian neoplasm: In order to investigate whether higher baseline ERV expression may affect immune cell infiltration of ovarian tumors, we calculated Pearson’s correlation coefficients between the expression of each of the 25 207 ERV repeats from the OC TCGA analysis and the expression of genes for T cell markers CD8, CD4, CD25, and activated or exhausted T cell markers LAG3 and PD-1, within the same samples.