Arg244 is a position commonly mutated in LCAT genetic disease (R244G (McLean, 1992; Vrabec et al., 1988), R244H (Pisciotta et al., 2005; Sampaio et al., 2017; Strøm et al., 2011), R244C (Charlton-Menys et al., 2007), and R244L (Castro-Ferreira et al., 2018)) and its side chain forms unique interactions in the observed active and inactive states of LCAT. Here, LCAT is linked to hereditary disease.