The Lucena 1 cell line, derived from the K562 human chronic myeloid leukemia cell line, shows multidrug resistance (MDR) due to selective pressure from vincristine supplementation. A proteomic analysis comparing K562 and Lucena 1 revealed qualitative differences. The ATP-dependent efflux pump, Translocase ABCB1, which is crucial for drug resistance, was a focus. Tubulin analysis identified an exclusive isoform, Tubulin beta 8B, in Lucena 1, potentially affecting resistance mechanisms. Additionally, Rap1A and Krit1 association in cytoskeletal regulation, along with STAT1 presence linked to urea cycle and tumor development, shed light on Lucena 1's unique biology. Increased Carbonic anhydrase I expression suggested a role in pH regulation. COP9, a tumor suppressor targeting p53, was discovered, further highlighting Lucena 1's complex molecular landscape. This study provides insights into the MDR phenotype and its multifactorial consequences in cellular pathways.