Measured C III]/He II versus C III]/C IV ratios for GN-z11 shown along with predictions from photoionisation due to AGN (circles) and star formation (stars) from Feltre et al. (2016) and Gutkin et al. (2016) in the range of Z/Z_⊙ = 0.066 − 0.131 and gas densities in the range log₁₀(n_H)/cm⁻³ = 2 − 4. Based on the observed line ratios, neither photoionisation from AGN nor star formation alone can conclusively explain the observations, placing GN-z11 right between the model predictions from the two.