Finally, we investigated the impact of pirtobrutinib therapy on chemokine production, considered hallmark biomarkers, and the BCR signal transduction pathway induced by diverse BTK and PLCG2 backgrounds in CLL lymphocytes obtained from patients on pirtobrutinib therapy (NCT03740529, ClinicalTrials.gov). This evidence concerns the gene BCR and B-cell chronic lymphocytic leukemia.