Accordingly, isolated drug‐tolerant tumour cells, isolated from rats that developed sarcomas post‐treatment, remained as sensitive to the treatment as parental cells, demonstrating that “resistance” to the TNF/Mel/SM treatment was caused by attaining a transient state called “persistence” without mutation (Hangauer et al, 2017; Viswanathan et al, 2017). Here, TNF is linked to sarcoma.