The differentiation of blood cells is one of the most complex processes in the organism. Regulated by the activity of transcription factors in time and space, it creates a specific signaling network. This network is characteristic for each type of blood cells and their differentiation stage. One of the signaling pathways that regulate the differentiation is Notch. The aim of this research is to explore the role of the Notch pathway and its relations to the enzyme poly(ADP-ribose) polymerase (PARP) in lymphocytes. PARP is an enzyme that participates in posttranslational protein modification and has a wide spectrum of activities. It can affect gene expression and signaling pathways through transcription factor modification and interference with their activities, as well as induce changes in chromatin structure. In this study, we analyzed the expression of a set of genes involved in the Notch and PARP signaling in several leukemic cell lines and studied changes in their expression after modulation of activity of these pathways. PARP inhibition caused changes in JAGGED1 ligand expression while inhibition of the Notch pathway influenced the expression of transcription factors from the Ikaros family (IKFZ1 and IKFZ3), regardless of signal path activity, but depending on the type of lymphocyte. A direct and rapid expression analysis for samples of limited size was also established.