SLC16A1 and neoplasm: Conversely, when the high %GP4 group was further subdivided by the dominant GP4 subtype, ICC or non-cribriform, the three resulting tumour types all showed significantly different [1-13C]lactate labelling (P < 0.05 for all; Fig. 6a) in the absence of notable changes in tumour ADC, Ktrans, and epithelial MCT1 density (P > 0.05 for all; Fig. 6a).