Clonal hematopoiesis (CH) is an age-associated phenomenon that has implication for multiple diseases, ranging from hematological malignancies, cardiovascular diseases, and solid tumor cancers. CH is defined by somatic mutations in the blood that gain a fitness advantage, proliferate, and then alter the immune system dynamics and disease outcomes. This thesis is divided into two chapter, exploring CH in solid tumor patients through complementary approaches.In the first chapter, I developed a non-invasive targeted molecular profiling assay and analysis pipeline using DNA from peripheral blood samples to detect germline and CH variants at low variant allele fractions. I accurately classified CH variants and revealed a strong correlation between CH and germline variants. My findings suggest that CH can serve as a valuable biomarker in the context of hematological and solid tissue malignancies. The second part of the thesis investigates the direct impact of CH on the immune landscape of solid tumors. I demonstrated that CH significantly alters leukocyte infiltration patterns, leading to increased immune dysregulation and poorer clinical outcomes. Through statistical analysis of immune profiling and clinical data, I show that CH amplifies anti-inflammatory pro-tumor signals in the tumor microenvironment, which may contribute to tumor progression. Together, these studies highlight the importance of CH in shaping immune responses in cancers and its potential as a biomarker for guiding treatment strategies.