Table 2.

Comparison of B7-H4 and PD-L1 protein expression in tumor and stroma for breast cancer intrinsic subtypes (merged data for Yale and UM Cohorts)

Yale and UM cohorts mergeda	B7-H4 positive		PD-L1 positive
	Tumor	Stroma	Tumor	Stroma
Triple negative	65/124 (52%)	43/124 (35%)	34/123 (28%)	38/123 (31%)
ER or PR positive/HER2 positive	23/50 (46%)	17/50 (34%)	4/47 (9%)	3/47 (6%)
ER or PR positive/HER2 negative	236/476 (49%)	137/476 (29%)	48/481 (10%)	37/478 (8%)
ER or PR negative/HER2 positive	23/51 (45%)	8/51 (16%)	6/50 (12%)	10/50 (20%)
p-valueb	0.79	0.08	<0.0001	<0.0001

^aTriple negative only Yale cohort is excluded from the pooled analysis

^bDifference in the proportion of positive B7-H4 or PD-L1 between subgroups using chi-square test. p-values are considered statistically significant if <0.05 and are indicated in bold