HC-5404-Fu is an inhibitor of PERK with anti-tumor activity. This compound inhibits the signaling pathway of the endoplasmic reticulum stress response. Additionally, HC-5404-Fu increases the sensitivity of renal cell carcinoma cells to vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors (TKIs). It holds potential for research into renal cell carcinoma, stomach cancer, metastatic breast cancer, small cell lung cancer, and other solid tumors.