A. KMS-18 and Karpas 299 cells were electroporated with a control siRNA (siControl), an siRNA targeting both isoforms (siA-1/3), or an siRNA targeting isoform 1 specifically (siA-1). Protein levels were assessed by immunoblotting 48 hours post-transfection. β-actin serves as a loading control. B. Twenty-four hours after electroporation with siControl, siA-1/3, or siA-1, KMS-18 and Karpas 299 cells were normalized and counted every 24 hours for 72 hours. C. Twenty-four hours after electroporation with siControl, siA-1/3, siA-1, or siA-1/3 + siA-1, Karpas 299 cells were normalized and counted every 24 hours for 72 hours. D. KMS-18 and Karpas 299 cells, transfected as in A., were stained 48 hours post-transfection with PI to evaluate cell cycle profiles by flow cytometry. E. Total RNA was collected from Karpas 299 cells treated with siControl or siA-1 for 48 h and subjected to reverse transcription followed by qPCR analysis of cell cycle inhibitor gene expression. *p < 0.001 compared to siControl.