TTK and neoplasm: Despite the levels of GFP-MPS1 being only 1.5-fold higher compared to endogenous MPS1 (band intensity of GFP-MPS1 vs endogenous MPS1; Figure 4A), the signal for MPS1 autophosphorylation at T33/S37 in MSD assay was robustly increased in DOX-induced tumours, compared to the non-induced tumours (Figure 4B).