CTGF or CYR61 were neutralized by the addition of antibodies at the indicated concentration to the culture medium when cells were seeded. (A–C) In co-cultures of 6x YAP5SA: 1x nuclear mCherry expressing cells (n-mCherry), CTGF neutralization increases the n-mCherry cells’ carrying capacity (Ymax), while decreasing their rate of growth (k). (D–F) Neutralizing CYR61 in these cultures has opposing effects of larger magnitude compared to CTGF. (G–I) Treating cells expressing empty vector (WT) with 1 μg/ml of CYR61 increases Ymax and decreases k. (J–L) YAPKD cells respond to exogenous CYR61 with an increase in Ymax and a decrease in k. (M–N) Cell size is not affected by the presence of anti-Cyr61 or anti-CTGF. (O, P) Adding recombinant CYR61 at 1 μg/ml also has little effect on cell size in YAPKDs and controls. (B), (C), (E), (F), (H), (I), (K), (L) n = 5 wells; mean ± SEM. (M–P) n = 5 wells; mean ± SD).