CTSS and neoplasm: IL‐4 promotes lung cancer growth by inducing protease activity of cathepsin in macrophages associated with tumor.51, 52 Similarly, IL‐6 also serves as protumorigenic cytokine promoting STAT‐3 and NK‐kB pathways which help in activating survival and anti‐apoptotic signaling.53 IL‐10 has also been found to have role in aggressive tumor growth and there expression by NSCLC cells leads to significantly poorer prognosis.54 Along with these cytokines, IL‐13 also promotes growth and survival of tumor cells, thereby suppressing cell‐mediated immunity.55, 56