Pancreatic cancer cells create a microenvironment by secreting cytokines and chemokines that recruit or activate stromal cells. This promotes desmoplasia -- an accumulation of extracellular matrix that contributes to fibrosis -- and immune evasion. Key players include myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), regulatory T cells (Tregs), and pancreatic stellate cells (PSCs). PSCs are the main source of extracellular matrix (ECM) deposition, and the TAM-PSC interaction enhances desmoplasia. These stromal cells help cancer cells evade immune surveillance by inhibiting CD8+ T cells through factors like IL-10, TGFβ, PD-L1, and IDO.