SFR surface density (Σ_SFR) as a function of the molecular gas surface density (Σ_H2) is shown using beam-sized regions (left) and clumps identified with Astrodendro (right) for NGC 3110 (top) and NGC 7469 (bottom). The blue and black points represent the two branches derived by applying the MARS method with breaking points in the log Σ_H2 for NGC3110 in the case of regions. The dark grey points correspond to the clump-based for both galaxies and the region-based method for NGC 7469. The brown and red solid lines are the best fits for the two branches, while the black line represents a one-slope fit. The Spearman’s rank correlation coefficients (ρ_s) and the power-law indices (N) of the derived best-fit KS relations are in the top left corner of each panel. The error bars indicate the mean systematic uncertainties in Σ_H2 of ±0.11 (0.10) dex (horizontal) and the extinction correction in Σ_SFR of ±0.27 (0.29) dex (vertical) for NGC 3110 (NGC 7469). The inverted triangles indicate upper limits. The grey dashed lines mark constant star formation efficiencies (SFE = Σ_SFR/Σ_H2).