Association of HERVs, embryonic genes, and their expression profiles with clinical features and unfavorable prognostic factors of CLL. Transcriptional levels and expression profiles of HERVs and embryonic genes and factors generated by PCA were used as biomarkers in multivariate general linear models that tested their association with clinical features and unfavorable prognostic values of CLL in all patients and in patients stratified according to therapy regimen. (A) Positive correlation between transcriptional levels of HERV-K and β2M values at the time of collection and association of expression between HERV-H and lymphocyte number in patients with CLL. (B) Inverse association of relative expression of NANOG with lymphocyte number in patients with CLL treated with chemotherapy. (C) In patients who received ibrutinib, β2M values at the time of collection were associated with pHERV-W expression, and lymphocyte count was associated with HERV-H expression and the CLL component 3 loaded on HERV-K and HERV-H. Comparisons were considered statistically significant for the following: P ≤ .050.