This study showed that knockdown of IGHG1 reduced the phosphorylation of extracellular signal-regulated kinase (ERK) and reduced expression (and therefore activity) of ferrochelatase (FECH) in colorectal cancer cells, revealing that IGHG1 silence might repress the progression of colorectal cancer through inactivating the MEK-FECH signaling pathway. This evidence concerns the gene IGHG1 and colorectal cancer.