SMPD1 and cancer: The Inhibition of SMPD1, a gene that regulates “ceramide sphingosine-1-phosphate rheostat” and drives tumour growth and immune escape in different types of cancer [59], through inhibition of epidermal growth factor receptor (EGFR) signalling and via activation of lysosomal stress has been proposed as the potential anti-tumoral effects of serotonin receptor inhibition, through fluoxidine, in GBM [60].