BMP4 and glioblastoma: Our studies detected five proteins that interacted with Fstl1 in glioma using Co-IP and pulldown experiments, i.e., DIP2A, CD14, BMP4, ActR-IIB, and follistatin (Fig. 4a and Supplementary Fig. 10A), and the mRNA levels of MGMT were only increased in GBM cells transfected with DIP2A-specific siRNA (siDIP2A) (Fig. 4b and Supplementary Fig. 10B).