More knee joint osteoarthritis (OA) in mice after inactivation of one allele of type II procollagen gene but less OA after lifelong voluntary wheel running exercise. - Lapvetelainen,T.; Hyttinen,M.; Lindblom,J.; Langsjo,T.K.; Sironen,R.; Li,S.W.; Arita,M.; Prockop,D.J.; Puustjarvi,K.; Helminen,H.J. (Osteoarthritis Cartilage, 2001)