TGFB1 and neoplasm: It was found that high TGF‐β1 expression levels promoted the growth of tumour cells by affecting molecules in the TGF‐β1 signalling pathway during the occurrence and progression of tumours, resulting in the abnormal proliferation of tumour cells; however, the proliferation of tumour cells also promoted TGF‐β1 secretion and accelerated the invasion of tumour cells into normal tissues 42.