To examine the effect of MAPK on the mechanism underlying the suppression of LCA-stimulated IL-8 upregulation by piperine, inhibitors of ERK (PD-98059), JNK (JNKi), and p38 (SB-203580) were used in combination with LCA treatment in human CRC HCT-116 cells. The gene discussed is MAPK8; the disease is Leber congenital amaurosis.