SFR versus stellar mass from Chang et al. (2015) for 180 spectroscopic Perseus cluster members (filled hexagons) and for 67 background galaxies (open hexagons). The colours indicate the position in the CMD (top) and the morphological type (bottom). The dashed diagonal line is the median relation from Chang et al. (2015), the solid line marks the demarcation between quiescent galaxies (below) and the SF sequence (above).