Based on tumour type and histology, culture situations can be adapted and customized, but mostly contain some additives, such as R‐spondin (RSPO), WNT3A, epidermal growth factor (EGF) and bone morphogenetic proteins (BMP) inhibitor Noggin, which help the stem cells to maintain their ability of differentiation and self‐renewal.27 The gene discussed is RSPO1; the disease is neoplasm.