Table 1.

The expression of AXL in drug-resistant cancers

Type of resistance	Drug	Cancer type	Model	Significance	Reference
Chemotherapy	Paclitaxel, carboplatin	Ovarian cancer	Human	AXL expression was higher in tumors with a poor response to chemotherapy	[59]
	Paclitaxel	Endometrial Cancer	Human	AXL level was lower in tumors with good chemoresponse than in those with a poor response	[58]
Targeted therapy	Osimertinib	NSCLC	Human	The response rate of patients with low AXL expression for osimertinib was higher than that with high AXL expression	[19]
			Cell	expression of AXL protein was also higher in osimertinib-resistant cells (H1975 OR1 and H1975 OR2) than sensitive cell lines (H1975)	[56]
	Erlotinib	NSCLC	Human	AXL significantly increased in NSCLC patients with erlotinib resistance	[57]
			Cell	Compared with sensitive cell lines (HCC827 and HCC4006), the mRNA and protein of AXL in erlotinib-resistant cells (HCC8267 ER and HCC4006 ER) were significantly up-regulated
	Cetuximab/panitumumab	Colorectal cancer	Human	Progression-free survival was significantly lower in RAS-WT patients with high-AXL undergoing anti-EGFR therapy	[61]
	Trastuzumab	Breast cancer	Cell	AXL was up-regulated in resistant cell lines (AU565R, BT474R, and SKBR3R) compared to corresponding sensitive cell lines (AU565, BT474, and SKBR3)	[62]
			Mouse	AXL mRNA level is significantly higher in vivo PDX–resistant model
			Human	Patients who later experienced tumor recurrence have higher expression of AXL in the initial diagnosis
	AZD1775	Small Cell Lung Cancer	Cell	Compared with sensitive cell lines (H1836, H82, H1048), the AXL expression of resistant cell lines (H1417, H865, H1930) was significantly higher	[63]
Immunotherapy	Nivolumab	ccRCC	Human	The objective response rate was significantly lower in patients with high AXL level. Survival rate of patients with AXL-high and PD-1-positive undergoing PD-1 block therapy was significantly lower	[60]