There are two hypotheses about KC renewal: 1) KCs come from bone marrow‐derived monocytes; 2) KCs originate from local intrahepatic progenitors and proliferate as mature cells (Diesselhoff‐Den Dulk et al., 1979; Jenkins et al., 2011; Klein et al., 2007; Nguyen‐Lefebvre & Horuzsko, 2015). The gene discussed is TBCE; the disease is keratoconus.