Another TGFβ downstream pathway that has been suggested as implicated in COL1A1 regulation is the phosphoinositide 3 kinase (PI3K)/Akt /mTOR (Mammalian Target of Rapamycin) pathway; this was suggested by studies on human lung fibroblast cells from pulmonary fibrosis patients treated with isoliquiritigenin (a natural flavonoid, with anti-inflammatory and anti-oxidative properties), resulting in a decrease in COLα1 (I), which was more pronounced in the presence of a PI3K/Akt inhibitor [60]. Here, TGFB1 is linked to pulmonary fibrosis.