Fig. 8

a Analysis of CACNA1H (Ca_v3.2) expression across the intrinsic molecular subtypes of breast cancer in clinical patient samples. The relative CACNA1H expression level (log2 normalised) was produced by the TCGA consortium through RSEM [36]. The TCGA tumour cohort consists of 845 tumours with 140 basal-like (Basal), 67 HER2-enriched (HER2), 420 luminal A (LumA), 194 luminal B (LumB) and 24 normal-like (N-Like) as determined by RNA-Seq based PAM50 allocations by the TCGA consortium. The PAM50 intrinsic molecular subtypes are based on the classifications of gene expression patterns previously described [66, 67]. This classification was performed by the TCGA consortium [35]. Horizontal lines represent data means with standard deviation and data points in grey. Statistical analysis was performed on expression levels of CACNA1H in basal-like compared to HER2-enriched and luminal subtypes using a one-way ANOVA with Sidak corrected multiple comparisons,(****p ≤ 0.0001). b Relative gene expression for breast cancer receptors ERBB2 (HER2), ESR1 (oestrogen receptor) and PGR (progesterone receptor) within each quartile of CACNA1H expression. Statistical analysis was performed using a one-way ANOVA with Sidak corrected multiple comparisons, comparing expression levels between the highest and the lowest quartile for each gene (*p ≤ 0.05, ****p ≤ 0.0001). c Ca_v3.2 overexpression in SKBR cells (SKBR3 EGFP) did not increase expression of hormone receptors or proteins involved in oestrogen-receptor mediated signalling TFF1, FOXA1, quantified using RT-qPCR. Results are expressed as fold change normalised to EGFP MOCK (n = 3 ±SD)