X-ray luminosity function calculated for 1.1 ≤ z ≤ 2.0 candidate clusters in the CFHTLS D1 and D4 fields. The filled circles show the X-ray luminosity function for flag  ≤ 3 cluster candidates only, whilst the open circles show the result for all candidates with flag  ≤ 5. The solid line shows the predicted luminosity function based on our survey geometry and WMAP 7-year cosmological parameters. The dashed line shows the same but with the WMAP 7-year Ω_m and σ₈ parameters reduced by 2σ.