HSPA5 and non-small cell lung carcinoma: Aside from these well-known mechanisms, the modulation of endoplasmic reticulum (ER) stress response elements such as proapoptotic CHOP (CCAAT/enhancer-binding protein homologous protein, growth arrest and DNA-damage protein 153 (GADD153)) and prosurvival GRP78 (glucose-regulated protein of a 78 kDa molecular weight, binding immunoglobulin protein (BiP)) is involved in the gefitinib-mediated cytotoxicity of NSCLC cells [9,10,11].