The TRP2 allele of COL9A2 is an age-dependent risk factor for the development and severity of intervertebral disc degeneration - Jim, J J; Noponen-Hietala, N; Cheung, K M; Ott, J; Karppinen, J; Sahraravand, A; Luk, K D; Yip, S P; Sham, P C; Song, Y Q; Leong, J C; Cheah, K S; Ala-Kokko, L; Chan, D (Spine, 2005)