TGFB1 and Low back pain: Correlation analysis of the relationship between multifidus morphology, TGF-β1 protein expression and chronic LBP, dysfunction in the LBP group was performed using Pearson correlation coefficient and the results showed a strong correlation between multifidus CSA and ODI (R = 0.659, P < .01) and VAS (R = 0.530, P < .05).