YKL-05-099 is a potent and selective small-molecule inhibitor targeting the KRAS G12D mutant protein, which is commonly found in several aggressive cancers, including pancreatic, colorectal, and non-small cell lung cancers. Its primary application lies in cancer research, particularly in the development of targeted therapies for tumors driven by the KRAS G12D mutation—a genetic alteration that has historically been difficult to drug. The compound enables researchers to probe the biological role of KRAS G12D in cellular signaling pathways, especially the MAPK/ERK pathway, which regulates cell proliferation and survival. By selectively inhibiting this mutant form of KRAS, YKL-05-099 helps suppress downstream signaling, leading to reduced cancer cell growth and increased apoptosis in preclinical models. Due to its cell permeability and stability, YKL-05-099 is widely used in in vitro and in vivo studies to evaluate the therapeutic potential of KRAS G12D inhibition. It serves as a valuable tool compound for validating pharmacological strategies and guiding the design of clinical candidates. Its application supports the advancement of precision oncology by contributing to the understanding of how direct KRAS inhibition can be leveraged for effective cancer treatment.