Sequence analysis of al(VI) and a2(VI) chains of human type VI collagen reveals internal triplication of globular domains similar to the A domains of von Willebrand factor and two a2(VI) chain variants that differ in the carboxy terminus - Chu, ML; Pan, TC; Conway, D; Kuo, HJ; Glanville, RW; Timpl, R; Mann, K; Deutzmann, R (EMBO J, 1989)