For example, V139I, K191E, V511I, M535L, N559T, M570I, I647V, and M676V each had cosubstitutions ranging from 8 to 21 instances with respect to K627E. Although S286G, R340K, M473V, K526R, T569A, and A588V were observed (Table 3 ), their association with K627E was seen in four or fewer instances.
Source: wiktionary