In contrast, Src (proto-oncogene, non-receptor tyrosine kinase; also called c-Src) showed a significant up-regulation in KC compared to control group (p = 0.0497), and no significant difference of NICD (intracellular domain of the notch protein) expression between KC and control groups was detected (Fig. 4). The gene discussed is NTRK1; the disease is keratoconus.