EGF and cancer: Classical culture media for cancer organoids usually contains the following niche factors: B‐27 supplement, nicotinamide, R‐spondin1, noggin, N‐acetyl‐l‐cysteine, A83‐01, SB202190; fibroblast growth factor (FGF) 10, epidermal growth factor (EGF) and Y‐27632.21, 22, 24, 31