PNG bias parameter p as a function of M_halo for different mass definitions. The green symbols represent our choice for the fiducial analysis (M_200c), while the grey dashed line represents the universality relation (p = 1). The shaded areas represent the 1σ, 2σ and the 3σ regions (from darker to lighter respectively) around the value of p we find in Eq. (19). Masses are shifted for visualisation purposes.